XM8 Assault Rifle

I’ve mentioned before that the biggest search engine draw to MO has been the XM8 assault rifle. Stryker searches bring in a lot, as well, but I’ve got an entire category devoted to the new combat vehicle and only one post about the new rifle.

Folks must be desperate for info on this baby. For a basic intro to the XM8, go to my previous post.


The XM8 (M8 if it’s adopted) assault rifle is a proposed replacement for the current M16 rifle and M4 carbine, the standard infantry weapons in today’s US military. The XM8 action is based upon the Hechler & Koch G36, a tried and true infantry weapon with a reputation for toughness and reliability. The XM29 OICW, which combined both an assault rifle and a smart grenade launcher, turned out to be too heavy, fragile, and expensive. The rifle part of the XM29 was adapted to become the XM8. The smart grenade launcher part of the XM29 is being developed separately as the XM25.

xm8b.jpg The XM8 is a modular weapon that can be adapted to different roles fairly easily. It can use any of four barrel sizes: 9″, 12.5″, 20″, and heavy 20″.

The 9″ barrel makes the weapon a submachinegun-like personal defense weapon (called the Compact Carbine) that would be ideal for vehicle crews. Also, I imagine that Special Forces types would find it useful for urban raiding missions and the like. With the buttcap (as pictured on the right, second from the top) it is less than 21″ long overall.

The 12.5″ barrel is the standard set-up, and with the adjustable buttstock, makes the Baseline Carbine variant. With the stock fully extended, it is 33″ long, the same as an M4 (which has a 14.5″ barrel). It weighs in at about 6.4 lbs, with a goal of being reduced to 5.7 lbs. The M4 with comparable accessories weighs nearly 9 lbs. The pic at right shows an XM320 side-loading detachable grenade launcher mounted.

There are two versions of the 20″ barrel. There’s a standard weight match-grade unit for sharpshooter work and a heavy-duty machinegun unit with a folding bipod for use as a sustained fire automatic rifle.

The XM8 seems to be an aberration in the military procurement sector. It is a model that seems to improve upon its inspiration in terms of cost and weight, while sacrificing none of the qualities that made the original so good. An XM8 Baseline Carbine, with its integrated sight, will cost around $1800. An M4 equipped similarly costs over $2500. That translates into a savings of $2.4 million to equip a 3,500 man brigade.

Cost notwithstanding, the biggest advantage of the XM8 over the M4/M16 is almost certainly the new weapon’s durability and resistance to jamming. The manufacturer claims that the XM8 can fire over 15,000 rounds without lubrication or cleaning, even in harsh conditions. While I seriously doubt that those numbers would translate into the field, it is indicative of the weapon’s reliability. The BARREL LIFE of an M4 is rated at 8,000 rounds.

The XM8 achieves this phenomenal reliability in part due to a unique gas-operated pusher-rod operated bolt. This system does not send carbon gasses into the receiver with every round like standard weapons, and therefore reduces greatly the amount of propellant that could potentially foul the action or attract material that could. Additionally, the seal between the bolt and the ejection port is much tighter than in current weapons, which will limit the amount of crud that can get in that way. Also, the weapon can be fired even if the action is flooded with water. No draining required.

While I doubt any squad leader would ever allow anyone to go an extended period of time without cleaning their weapon, regardless of manufacturer’s ratings, there is a fair amount of time savings still to be found. First of all, the XM8 can be field cleaned in 4 minutes. This compares to more than 10 or 12 minutes for an M4, which translates into a an extra bit of rest, patrol, or other duties for the XM8-equipped soldier. Weapons are cleaned at least twice daily, if not more, so this 5-8 minute savings is not insignificant when multiplied by three thousand soldiers in a typical brigade. Also, the integrated sight is zeroed-in at the factory and does not require continual re-zeroing in the field by the troops.

Dirty and jammed weapons seem to have contributed to the defeat of the maintenance group that included Jessica Lynch during the invasion of Iraq. Part of the problem seems to be that the Army-supplied cleaning lubricant isn’t effective, especially against the fine Iraq sand. But non-combat units probably don’t devote enough time to cleaning and maintaining their weapons. The XM8 could help alleviate that by reducing the time required to complete the task, which will increase the odds that the task is attempted, and by being more forgiving if/when the task is forgotten or ignored.

Another nifty feature is the ability to be quickly adapted to fire AK-47 ammunition. This would be especially useful in Iraq, since there’s more AK-47 ammo in Iraq than there is sand.

For a comprehensive comparison of the XM8 Lightweight Modular Weapons System (LMWS) Baseline Carbine to the current M4, check out this .pdf. Keep in mind that it was published by the manufacturier of the XM8.

For an 18 second video of a full-auto firing of the XM8, check this out. HK-USA also has what amounts to a product brochure for the XM8 here. It includes drawings of many of the interchangable components of the XM8 system.

The XM8 has recently finished heavy testing. The next step is going to be to equip two full brgades with the weapons. I’ve been unable to learn which brigades get to be the lucky ones to try a new standard weapon out for the purposes of working out all the bugs. Maybe they haven’t been determined yet. I’d suggest that, in addition to the the big tests, some individuals or small units deployed in Iraq and Afghanistan get them. We must learn how these things really perform, and no amound of testing and simulation can teach as many lessons as a few minutes on a real live battlefield can.

For all the apparent good news surrounding the XM8, one basic issue remains the caliber of round our troops need to be firing at the bad guys. The XM8 will fire the NATO standard 5.56x45mm round, the same as the M4 and M16. There is a lot of grumbling among the troops that this round is insufficient, especially when fired from an M4’s shorter barrel. The standard XM8’s barrel is two inches shorter than the M4, so this issue will be even more pronounced.

This is a very controverisal subject, with feverent believers on both sides. Many who think that a larger round, like the 6.8mm or the good ol’ 7.62mm, is needed admit that the 5.56 might be sufficient if the type of ammunition was altered instead of the size. There have been many reports from Iraq, Afghanistan, and Somalia that the current round just doesn’t cut it. I don’t know enough to have an opinion on the matter, but it certainly seems that something needs to be done.

Airborne Combat Engineer had a post back in November about the XM8 and the ammuntion debate. He notes that we’ve already got so much refinement and investment in the current M16 and M4 that it seems like a waste to start over with a new weapon. He asks why the current weapons can’t just be up-gunned with the new 6.8mm uppers that will soon be hitting the market. That’s a very good question, and one that I hope our military seriously considers.

Back in August I thought the same thing. But, if the XM8 performs in the field like it’s performed in the tests, we might be better off in the long run if we make the change. The cost, reliability, and adaptability of the new weapon may outweigh our experience with the current one.

UPDATE: A Sliding stock for XM8 compact carbine PDW has been added to the mix. Pictures and more.


  1. A lot of people on this site are talking about full auto. Not to say you people aren’t thinking, but the first round fired is the only round that has any chance of hitting a target outside of 40m. So I say go back to the 7.62 NATO and increase the weight of the gun to reduce the recoil. I have a cousin in Iraq right now, and the only thing he’s complaining about is the weight on his back, not his weapon or ammo’s weight. We need to make our military more leathal and the pea shooter that we are making won’t help us win any battles. The M8 kind of reminds me of the SA80A1. That weapon could take down targets when its gas system wasn’t leaking, which it always was. The Brits had to send all of the rifles to Germany for repairs on the gun. Only with the M8, we’ll need to buy a entire new set of barrels because the round will be highly ineffective in combat. The M8 has one good thing going for it though, it is cheaper than a M4 with similar equipment.

  2. This is designed to be a special forces weapons anyways, all the comparisons are between the xm-8 and the m-4a1, the xm-8 is designed to replace the m-4a1, and more than likely it was designed in mind for the navy seal type operations where they would have their rifled submerged and need fully automatic suppressing fire.

  3. Although I’m sure that special forces will use the weapon a lot and appreciate it’s modularity, this is intended to be the main weapon in the US Army, replacing the M4 and M16 as the standard assault rifle and carbine. This is not a special forces only project.

  4. Lots of interesting comments on this post. 5.56 vs. others-Yes m855 with a barrel under 18′ is not the best for shooting people. It would be nice to have a weapon that doesn’t require ‘double taps’. 6.8MM sounds like a great caliber, I was thinking this about 6.5 mm at least 10 years ago. Will the Army adopt a new caliber?-doubtful. barrel length-The only possible reason for a 12.5′ barrel on the ‘standard’ XM8 is to meet some arbitrary length requirment set by the Army. Some articles claim a higher velocity from the standard XM8 than the m4. Do people really believe that a 12.5’barrel will give more velocity than a 14.5′ barrel? How is this possible without a change in ammo? ‘Quick user interchangeable to 7.62 AK ammo’ Not possible without changing the barrels and bolts at a minumum. Does anyone believe the guns will be issued with more than one barrel and bolt and that soldiers will carry these extras with them?The people that believe this garbage are the same people that set a requirement for a new MILES laser for m16’s that curves mimicing the curved path of a bullet.(impossible according to the laws of physics) Gas piston’s-are not new or unique. They are the norm for most automatic rifles. I’m glad to see the XM8 has a indirect gas system. Backup sights-I’ve heard the XM8 sight will have some sort of crosshair etched onto the glass so you still have a aiming point when the battery dies. I have worried about the reliability of ‘scopes’ of any type, but it hasn’t been much of a problem in the past few years. Zeroed at the factory is good, but it should still be adjustable so it can be zeroed by the user. Heavy barrel support weapon-any support weapon must be belt fed and have quick change barrels. Once again people that think you can put a bipod and a heavy barrel on a rifle and have it replace a belt fed LMG are the same people who ask for laser beams that curve. SR47-Most SF bn’s have AK47’s and AK74’s in their armsrooms. They are cerainly easy enough to obtain in iraq and Afghanistan. If team guys want a 7.62×39 rifle so they can use indigenous ammo for resupply why not adopt a rail system to a AK47 and carry it instead of a M4? Wouldn’t it be easier for some company to make a rail system for AK’s than design and adopt a whole new rifle? If I could mount my PeQ2, tac-lights and optics on a AK I would gladly carry it in place of my M4. AK rail systems could be IMPAC purchased by individual units just like a camelback or tool set without dealing with the legal/regulation conflicts of buying weapons.

  5. To address the M16: Originally it was designed to use flake poweder but was changed, by the ammunition plant, to ball powder since they had alot on hand that they wanted to get rid of and since it offered range advantage. Ball powder burns faster but burns dirtier. Giving you a weapon that fired a faster, longer distance weapon but it made the action move much faster than originally intended. That coupled with the extra fouling stressed and wore out the rifles much faster. Other problems were un-chromed bores that lead to faster fouling of the barrel. New powder, chroming of both barrel and bore, as well as the addition of a forward assist, cleaning kits, and modified training to include cleaning helped alleviate the problems. Modern additions to reliablity was double feed ramp cuts into the upper receiver and barrel extension as well as increased power extractors in the M4. As for accuracy, the M16A2 and A4 are the worlds most accurate infantry rifle. There is a theory that the direct gas impingement system aids in accuracy, though I can neither remember how or where I had read the information. I digress, the M16 and M4 are supremely accurate. Out to 500 yards, it’s quite possible to land 10 out of 10 rounds on a man sized target. And that’s just 50 rounds short of the rifle’s maximum range on a point target. Maximum range on a area target is 800 yards. Because the M855 rounds do most of their due to fragmentation, the optimal ‘kill’ range of the 20′ bbl M16 is approximately 140 to 150 meters. After which, velocity drops below 2700 fps where the M855 round reliable fragments. With the M4’s 14.5′ bbl, the range is further reduced to 45-50 meters. Fragmentation from an 11.5′ barrel is limited to 12-15 meters. This is using a standard button cut rifle barrel. For the exact reason I stated above, SOF have either used a heavier caliber rifle or heavier projectiles. Such as the 6.8mm SPC and the 5.56mm 77gr Black Hills cartridge. There are advantages and disadvantages to each cartridge: The 6.8mm SPC has smaller capacity in same length magazines than the 5.56mm, usually about 26 or 28 rounds versus 30 –which needs to fit in the standard M16 magazine pouch — as well as needing a whole new barrel and bolt. The 77gr 5.56mm Black Hills cartridge has proven to have much better terminal balistics than the 62gr steel penetrator M855 but it lacks the range/velocity of the M855 and is not as flat shooting. Velocity can not be increased in the 77gr cartridge safely due to pressure concerns. Earlier, someone mentioned higher velocity in the 12.5′ XM8 versus the 14.5′ M4. The stated velocity increase from the XM8 may result of the different barrel Heckler & Koch uses. H&K uses the newest barrel construction technique called hammer-forging which produces a polygonal bore, usually an hexagon, instead of familiar lands and valleys you see in most button cut barrels. The polygonal bore makes a tighter seal, causing less gas blow by, and utilizes propellant far more efficiently. This makes for faster velocity for the same barrel length. As a side effect, the hammer forging method makes an incredibly tough barrel that would take the abuse that would make a standard barrel burst. Also, H&K looks like they use a Vortex style flash supressor, at least on the shorter barrels, for the XM8 which is known to not only eliminate flash from even short barrels but to increase accuracy and velocity by preventing turbulent air in front of the projectile as it leaves the muzzle. Barrel and flash suppressor together might make enough of a difference to increase velocity even in the shorter 12.5′ barrel. To conclude: The XM8 would only be ideal to me, as a Marine, if it were increased to either 6.8mm SPC or Alexander Arms 6.5mm Grendel. And that cartridge selection is a debate for another day.

  6. good reply. I am familiar with polygonal rifling, but I never considered that it would result in better sealing or higher velocity. I can definately believe that Polygonal rifling offers increased barrel life and less fouling simply because you don’t have lands and grooves cutting into the bullet. Barrel length…..well I believe weapon length is more important than barrel length. A telescoping stock is necessary these days in order to adjust the length for body armor. A rifle with a long stock like the m16a2 is akward with body armor. A m16a1 or AK will work Ok with or without. I think a M4 with a 18′ barrel would be plenty short for CQB and still offer long range. There is no appreciable loss between 20′ and 18′. Bullpups are the easiest way to get a really short rifle, but they don’t balance or handle as well as a conventional rifle. My thoughts on the best infantry rifle…1 shot stops 0-300M. Shoots groups 2MOA or less. Has a crisp trigger less than 5 lb. has sturdy iron sights with the front sight at the end of the barrel. Handguard all the way to the end of the barrel. Modular rail system. Telescoping and side folding buttstock. compensater as good as AK74 that also is machined for attaching suppressor. Reciprocating charging handle, so there is no need for a forward assist, and when the weapon won’t cycle correctly you can still rapidly cycle the weapon by hand. Tritium front sight. The ‘Safety’ is operated with the trigger finger, encouraging new soldiers to patrol with their trigger finger on the safety instead of the trigger semi/auto selector is a thumb operated lever that returns to semi when released. Gas piston with 3 position adjustable regulater High, low, off. Fires a bullet between 90-110grains at 2800+fps. Ammo comes packed in a combat mix. 1 framenting bullet, 1 AP, 1 fragmenting tracer. Rifle has a durable green/brown camo finish… maybe a epoxy coating? All parts are made as ergonomicly as possible to aid the rifleman in hitting the target rapidly. Has standard mags of 25+ rounds for patrolling and standard use has a large cap mag of 50+ rds for inserting when beginning a attack or when large cap is needed……. This rifle must be totally unstylish it must not be appealing to queers, women, socialists, or people from europe. It must inspire confidence in the soldier when he holds it. You must be able to beat someone to death with it if you run out of ammo without breaking it. that’s my thoughts..

  7. There are a lot of intelligent comments here. We obviously have some engineers in the house. I can certainly understand the popularity of the m-16 family of weapons and the excitement revolving around the xm-8. I almost hate to say it because I like them myself, but I think that these designs have become outdated. If you look back at the history of rifles and the mishaps that occurred over the years within their chambers I can understand that some people may have developed an aversion to putting the chamber farther back into the buttstock such as in a bullpup. It made sense to put the chamber farther forward on the rifle to protect the shooter from firing mishaps. A bullpup is a much more efficient use of space. No matter what the cartridge, why waste its potential by shortening the barrel so much? A bullpup has the ability to incorporate longer barrels into a shorter rifle. This means that the ammunition’s potential is utilized. It means quieter shooting from the barrel and more muzzle velocity. The bullpup design does not sacrifice accuracy, weight or reliabity. Drawbacks of the bullpup design include mechanical changes that need to be made to accommodate left-handers, noise for the shooter can be intense with the ejection port near an ear and the triggers aren’t as crisp as with the m-16 family. Take a look at the Tavor. The Israelis got it right. B, you said that bullpups don’t handle well??? You seem like a bright guy but get real. With the weight to the back of the rifle you can acquire targets much faster. Take a baseball bat by the skinny handle with one hand and try to quickly move it around and point it at things. Turn the baseball bat around, hold the fat end with one hand and try the same thing. If that doesn’t get the point across, try it with a doughnut on the bat. With the bullpup, you get more feet per second from the same ammunition; you get faster target acquisition and less user fatigue. You also don’t have to muck around with changing your buttstock length. Why do you think the Austrians, Australians, English, French, Israelis etc. are going to the bullpup? It is a better design. Don’t knock it until you try one.

  8. The Tavor: A stuby little powerhouse. Check this puppy out. http://www.isayeret.com/weapons/assault/tavor/targal.htm

  9. Concerning the ejection of bullpup, it should be noted that FN Herstal has developped a bullpup, the F2000, that ejects spent cases in front of the weapon, thus allowing change of should and instant left-handed usage (IIRC, most CQB use of bullpup is prohibited by the need to rapidly change shoulders – the SAS use M4/C8, the GIGN use SIG 551, in place of their bullpup national rifle).

  10. A question I have is this: Our troops in Iraq and Afghanistan are equipped with M4 and M16s which have proved unreliable and and to have lack of range in the desert and high elevations of these two theaters. Why not reissue the M14 to soldiers in the areas. For a bit more money, the rifles could even be improved a bit; possibly shortening the barrel to 15 or 16 inches and giving the rifle a collaspable stock. Second question: Why do we need an entirely new rifle? Granted, the M4-M16 series has had its problems, but it has overall proven itself as a good combat weapon for about forty years now. Sure, it is a bit underpowered espessally in desert areas, but do we need to discard it completely? Instead of a new rifle, it seems both economically and tactically smarter to upgrade the current rifles. We could change the gas system on the rifle to a more reliable one, like what the XM8 or even the AK rifles use, and upgrade the caliber to the 6.8x43mm SPC or the conceptual 6.86x40mm ARC (preferably the 6.8 as it is much more powerful). It would (probably) cost less and would be better for the troops who already are familar with the M4-M16 rifles Final question. Evidently, if adoption of the XM8 is inevitable, it does not solve the problems with the 5.56mm cartridge. It was mentioned that the XM8 carbine would be able to be converted to fire the ubiquitus 7.62x39mm. One of the arguements against upgrading the XM8 to fire (as standard ammunition) the 6.8mm is that there is so much 5.56mm ammo around that if a soldier equipped with a 6.8mm gun ran out, he would be defenseless, and all the 5.56 rounds availible to him (or her) would be useless. Well, if the XM8 can be converted to fire AK-47 ammunition, couldn’t it have the 6.8mm ammo as standard with the ability to convert the barrel and bolt to fire 5.56 if needed? If no one wants to post a response, if you could email me possible answers, that’d be great!

  11. PaulCG: Regarding your idea of using M14s instead of the M16/M4, it’s already happening, at least with squad sharpshooters. I’ve given the subject a fair amount of coverage here, beginning with http://murdoconline.net/archives/000909.html . Here’s a list of every post that mentions the M14: http://www.murdoconline.com/cgi-bin/mt-search.cgi?IncludeBlogs=1&search=m14 . Most of them are centered on the exact points you bring up. I think you’ve also got a good point about the 5.56 ammunition issue. Check out this post and especially the comments for more thoughts: http://murdoconline.net/archives/001138.html . Airborne Combat Engineer, who comments on the post, is a fan of the 6.8 SPC. Check out the post he links to in the comments. He’s got a lot of good other stuff on his site, so check it out. As for the possibility of adapting weapons to different ammunition in the field, I think that will end up being a pipe dream, no matter what rounds they go with. That’s just too much stuff to be lugging around. Maybe it could be done on a large scale before a major operation or something, but it would also throw off all the training. Special Forces types would probably like the capability, but as for the rank and file troopers there’s probably no way to easily make it practical. I don’t know what’s all involved, so maybe I’m wrong about that.

  12. Yeah, good point with the ammunition. I thought it was a good idea too, but it does seem a little too, for lack of a better term, utopian. Another question I had was about the 6.5 PPC/Grendel. I was reading an issue of Special Weapons for Military and Law Enforcement where possible 5.56 replacements were being tested. The 6.5mm PPC was clearly superior to the 6.8mm SPC in both range and energy. I understand the military has tested the 6.5mm as well but they are still favoring the 6.8mm. Any explainations?

  13. One more thing: Is the switch to the XM8 a for sure thing with the U.S. military, or is it still just a proposal?

  14. While it’s not a done deal, it looks all but certain. I don’t have any ‘inside’ info, only what can be found from public sources, so who really knows? Two brigades are going to equip with the XM8 for extensive field testing, hopefully one of them will be in Iraq for a ‘real-world’ test. It appears that it’s going to be adopted, and that it’s going to be 5.56.

  15. I don’t mind saying, the fact that it’s going to be 5.56 really sucks. I support the military wholeheartedly but I think they’re making a big mistake sticking to the already problematic 62 grain 5.56 NATO. I’ve heard a lot of reports from soldiers who started loading up with Black Hills 77 grain 5.56 ammo, but even those reports are mixed. While these rounds hit slightly harder, they are less accurate and the degree of improvement in stopping power is so slight it doesn’t even seem worth it. These reports worry me since I am going into the Navy in about 3 years and, hopefully, will make it through BUD/S and into the SEALs. I don’t want to be armed with a weapon that is weaker than the current ones already issued! One nice thing is that US SOF personnel seem to use what works more than what’s issued. I recently saw a picture of an MP5N that had been rechambered by its user to fire .40 caliber rounds (it WAS an MP5N, not a UMP40, just clearing that up before someone corrects me). So, I’ll tell you one thing, if I get on the Teams, if all I get is that M8, I’m changing the receiver for the 6.8mm SPC. Hopefully I won’t have to do that; I’m hoping that XM8 firing the 5.56 will get enough complaints before it heads into production to upgrade the caliber. If H&K doesn’t do that, we might as well scrap both the M16 and M8 programs and go back to the M14. It’s hands down the best rifle for the desert anyway; It’s reliable in the sand, it has long range, and it’s hard hitting.

  16. Don’t go blaming 5.56mm on the rest of NATO. We blame it on the Americans. If you want a good modern assault weapon then they are out there already. Take the FN F2000: this is in its early days but what a tool. Or the Steyr AUG: more proven than the F2000 and if the Saudis are using it then its possible it might work in the desert???. Try not to make the same mistake as the British and reinvent the wheel just to prove you can. Having said that, the L85 (SA80) is a fantastic tool for hitting what you are shooting at. It has problems for left-handers and for firing to the right flank but those problems are normal for many current weapons. The .303 farce that dogged the british for 2 generations has buried us in a culture of irrational weapon cleaning and this has affected the L85’s career by causing us to concentrate on cleaning the wrong things. Thats not the whole story though and basically a small round will breed small mechanisms and they are shit to clean. On the subject of small rounds it all about momentum and energy. Momentum is mass times velocity and is the ‘knock ’em on their backsides’ sort of effect. Energy is half mass times the square of velocity and the ‘carve the guts out of them’ effect. Both 5.56mm and 7.62mm have high energy due to muzzle velocities of Mach 2.5 to 3. Additionally 7.62mm has higher momentum due to higher mass and this serves to ‘knock ’em on their backsides’. All combat weapons of whatever calibre will continue to weigh about 4 to 5 kilos if you want to hit the target. Decades ago the Russians proved that an infantryman should carry no more than 40 pounds into battle yet we are routinely carrying nearer 40kg and the bastards think up more for us to carry every year. The answer to the weight issue is not in the personal weapon or in its ammunition.

  17. I don’t think that the U.S. is going to be interested in a bullpup weapon anytime soon, jimf. The military has repeatedly turned down bullpup designs including the Steyr AUG, the SAR21 (that rifle made in Singapore), and the Tavor to name a few. As good as the F2000 sounds, I’m pretty sure it’s not on the list of possible M16 replacements. Frankly, I think most of the hype over the F2000 is from gamers ‘seeing what it can do’ in Splinter Cell. About the F2000’s forward ejection, I heard the cases travel down some kind of tube to the ejection port. That sounds a jamming problem in the making. Also, the bullpup design doesn’t change the fact that the 5.56mm round still doesn’t hit very hard even from a 20 inch barrel. I say, if we’re going to upgrade to a new rifle, whatever we do, go with the 6.8mm round.

  18. I wonder if the reluctance to move away from the 5.56mm round is mainly political. Being the flagbearing ‘standard’ NATO rifle round, stockpiles of ammunition across America, Europe and elsewhere exist to equip 5.56 mm armed troops. I’m sure, logistically, introducing a novel 6.8 mm round would involve a lot more supply difficulties – especially in multi-national campaigns. I’m sure Europeans wouldn’t like it, as I bet America pushed for the 5.56 mm standard, and now if we just abandon that standard our allies might be wonderng why we can’t make up our minds.

  19. That is certainly a great point, Brian. And I believe that you’re right that the US led the push for the 5.56 NATO standard. One problem with the stockpiled ammo argument, though, is that the US military is currently in danger of burning through it’s inventory of 5.56 ammunition. There have been a number of stories in the press about our inability to cover our usage in Afghanistan and Iraq with current production capacity. We could always switch to 6.8, and agree to buy off some NATO stockpiles of 5.56 to cover us in the meantime. That might soften the blow a bit. Of course, we’d just turn around and try to sell them XM8s.

  20. when do I get my xm8 cause i need one really bad for somethin that I have been planning for a long time if u give me one ill tell u what it is so plz think about getting me my xm8 ill pay you 50 dollars for it

  21. The XM8, basically a G36C (because of the 12.5inch barrel) with intergrated optics, converted magazine receiver, and retractable stock. Since we will be getting new polymer magazines any way, so tell me why America needs to be the lone wolf with its weapons when it would be cheaper to just buy the G36 series of rifles. The Army already canceled the RAH-66 Comanche reconissance helicopter after they spent 7 billion on it. Our military doesn’t get as much money a people would like to think, so could we just save on not doing R&D and testing on a rifle that is the same as a rifle that other countries use?

  22. I have an SL8 and an AR. They are both brilliant in their designs. I have 2350 rounds through the SL8 and the bolt still shines. Never dirty, never a malfunction, eats all kinds of ammo, MOA accurate always. The indirect impingement is sweet. ( I still love my M4…) Since the M8 is based on the SL8/G36 design, I don’t think you can go wrong. If HK scales it up for the 7.62 so you have two series like Armalite did with the AR platform, then you have the best of both worlds and still can use the 100’s of millions of rounds stockpiled eveywhere. And range is a non-issue when an A-10 is just over the hill…

  23. AR-10T Baby. 7.62x51mm is the way to go. Ammo makes a big difference. Grunt’s will always get the lowest bidder. Special Forces will get their own stuff that is the best; Interesting how they go with the .45 Handgun and .308 Rifle round? They know what’s up! It’s a cost issue it turn’s out that is resulting in a weaker force.

  24. It looks like the 10th Mountain Division gets to test it now… http://www.wstm.com/Global/story.asp?S=2194829 And I coulda SWORN 6.8mm was still in the running, though maybe after all the 5.56 stocks are used up :/

  25. I was just wondering is there a reason why the army isn’t going to a bullpup design like the TAV-21 that way they could fit a 18 or 20 inch barrel and still keep the gun short?

  26. Hey edwin, when did they last change your diaper, you illiterate slob? If you’re not capable of quality conversation, then go dribble on your bib somewhere else.

  27. I’d rather them go with the M468. It actually ends up being more cost effective to simply replace upper recievers and ammunition than to replace entire weapon systems along with their accessories. However since they are intent on sticking with the 5.56 they could at least use a 5.56 APLP round which is pretty much a one-shot-drop as the round explodes inside the human body and can penetrate armor.

  28. First off I want to say that I love reading everyones post. I have learned a lot from them. I leave for ROTC training this Friday and will graduate in 2008 to go active duty for 4 years. It seems to me I will be using this weapon in the field and who knows by that time we might be inside North Korea. I own 10 fireamrs. one M4 and one Ar-15. The Ar-15 has a 5.56 Lower and a 7.62 upper receiver, and of course a 7.62 barrel. I always compare this with my 5.56 M4 which is a lot eaiser to control recoil wise. The 7.62 Has a nice nock down round, and it seems to put a lot bigger holes in things. The 5.56 round just goes through stuff and keeps going. I like the idea of a 6.8 MM round but this new gun might be a good idea. It looks like a gun from Starship toopers but Heckler and Koch do not make cheap wepaons. I own one of there MP-5 civilian versions, with the 9MM round. It is very thorough and does not Jam. I think the switch to the new weapons would be a good change, but like most people on here have been saying we need a better nock down round. Thanks again for all the great information!

  29. Glad to see our beloved 10th trying it out. As someone who owns a HK SL8-1, and M4 and AR 15 sporter target, the HK is far easier to clean and slicker to shoot. Shooting the HK is reminds me of a swiss watch compared to the clunking going on in the Colts. Put a couple of hundred rounds through the Colt or the HK at the range and the Colt is MUCH more difficult to clean, especially if you clean as thorough as the US Mil now recommends you clean them. Then there is the barrel, no comparision comrades, the HK is hand down better with it’s polygonal rifling. I;m just hoping the ban sunsets and HK sells a civilian semi-auto version. I’ll have at least one Colt for sale.

  30. Joe, I concur completely on the assessment of the HK SL8-1; I have one and it really is the Mercedes of semi-autos. It would be the ideal model on which to base a new weapon ( i.e. XM8). If HK can adopt the 6.8 SPC or the 6.5 Grendel into the XM8 package, the world would be a better place. And hopefully the ’94 ban will die and we can get a civilian (semi-auto only) version of the XM8.

  31. I’ve recently come over an article in the army times showing some new updates they’ve done to the XM8. The 101st airborne and the 3rd infantry have tested the rifle and loved it. There’s now an increased rate of fire, which I think is about 850 rpm. The bolt release catch is bigger. Plus a very new feature which shocked me, was the new rail sights they’ve added to the XM8. I guess the XM8 won’t be using the optic sights alone anymore. They’ve changed the barrel and optic sights as well. Such as a heavier barrel for the Automatic version and now have turned to the bird cage flash suppressor design as well. Even the handgaurd has been upgraded. I’ve also read that they bury the rifle and fire it to test jams. I guess that’s an effective way to find out.

  32. I have a military background but not as a frontline soldier, apart from the size of the ammunition which appears to need more stopping power, isn’t the weapon missing a bayonet. In close quarters battle, when anythings goes, and the gun jams/runs out of ammo, and physic violence is what is going to keep you alive, surely your chances increase with a bayonet fixed, rather than using the butt?

  33. What really puzzles me is that if this gun is so close to the G36 how come that the stock aint folding like the G36 is nor does it eject used cartridges downwards, and what good is it to have controls that work for left or right handed if the ejection port is fixed on the right side? :/

  34. Rakim, It’s close to the G36, not a duplicate which means it incorporates functional features into a new generation weapons platform. If you read the buttstock is adjustable in 5 settings as well as the option of a butt cap thereby reducing the whole cumbersome option of a folding stock. The reason for the controls being on both sides is ease of operation, both right and left handed soldiers can use it without having to switch up and cost seconds. As to Pauls post about no Bayonet, again if you bother to read it comes with a fixed bayonet lug just as the current M14/M4A1 variants.

  35. I don’t know why we just dont switch to the FN P90 rifle and Five-seveN pistols. Those little 5.7mm rounds are truly wicked and will penetrate body armor. I have fire the pistol and have found it to be pretty cool.

  36. There is a reason taht the 5.7 rounds are in pistols and sub-machine guns. They can’t engage targets past 200 metres. Although under that range they are king. They are good as side arms or for close range fire fights. 5.56 does have problems but does have upsides as well. It can punch through body armour but since it is so small it punches right people and doesn’t have any stopping power, which knocks the enemy back. One of the main reasons for having a small calibre is that it is light and you can take many.

  37. i like the xm8. it sounds like a good idea, but completly re-arming the military with it seems a little much. remember, the m-14 was never truly brought out of service because the SEALs use them and the marines use a modified version. i think the xm8 would be great for special forces who need a light and reliable weapon than won’t give out in an intense firefight. and for those long-range engagements, the marines use the 7.62×51 m-14dmr and special forces have the sr-25/mk-11 rifles of the same caliber. honestly, i think we should just use the ak-47. it is the most widely used gun in history. the ak has a reputation for reliability like no other. the vietkong beat us in vietnam with them and every other force we’ve gone up against armed with ak’s seems to have given us a hard time. we just dont use them because it would make america look weak. wouldn’t it have been big for soviet propaganda if the mighty americans addmited that they can’t make a gun as sound as the ak?

  38. I don’t know alot about this gun, but I like how it looks like the G36. It might not be like the AK, but I like most 5.56 caliber weapons. Thats just me though, plus it lightweight. Do you think that the XM8 can replace the G36?

  39. The XM8, as you probably know, is a varient of the G36. It won’t replace it, however, because the G36 is, correct me if I’m wrong, the standard issue of the German Army and probably a few other militaries I don’t know about. I acually heard awhile back that the Brits were considering adopting the G36 or a varient of it to replace problematic SA80 (which I’m told British soldiers hate and SAS troops won’t even touch). I think the reason the U.S. military is adopting the XM8 is because #1 It’s actually made here in H&K’s American plant unlike the G36 and #2 with the Germans opposition to Iraq, we wouldn’t want to give in and look like we have to look to the Germans for supplying our soldiers. This is probably the same reason we won’t adopt the AKM or AK-101.

  40. I’m STILL an advocate of the M14. I heard that the 82nd Airbourne is seriously considering making it standard issue in Afghanistan (I’m not in the service yet, so anyone from the 82nd or who knows about this, feel free to correct me). The Navy’s serface ships’ small arms lockers are usually filled with M14s rather than M16s or M4s due to the fact that a .308 can punch holes in small crafts. I think the best thing we can do is to take the current M14, shorten the barrel to about 16-16.5 inches, give it a new, folding stock with some sort of RIS for mounting accessories, and put a recoil buffer in that would make it more manageable in automatic fire.

  41. Switch to the AK-47? I don’t know about the newer AK-100 series but the AK-47 and AK-74 are nothing but durable, reliable garbage. Sure, they’re deadly up close but you start having a target at around 100 yards and you’ve got yourself a gun that is about as accurate as a diasy air rifle. The reason why you see a lot of them is because they are dirt cheap to manufacture and you can find them unaccounted for in abundance. The whole fall of the USSR and all. No real soldier would want to run around with an AK, especially when there are tons of better weapons you could choose from. As for the AK-100 series, I believe they fire the 5.45 round which is even smaller than the 5.56 and isn’t a favorable round. As for the M14, yeah it’s a real badass gun. Have you seen the SOPMOD M14 made by Troy industries?

  42. Most countries use the weapons they make, of course, like U.S. Military use M4s and M16s etc., but personally I’ll pick a weapon thats suitable for me. I still like the AK, I’ll USE an AK, but I still choose a 5.56 cal over a 7.62 cal(thats just me saying).

  43. Ok…well, we all probably agree that its time for the US of A to upgrade its primary assult rifle weapons system. Now…to do that obviously there are many factors to take into consideration. The xm8 seems to handle MOST of them very well. The few it MAY do not so well (like bashing an enemy over the head when you run out of ammo) are par for the course in any man-made device. I’m a operating engineer and believe me-no man made device is perfect. It seems that the designers goal is to offer a system that is light, lethal, reliable, flexible and accurate. The caliber debate goes on…5.56 will still kill ya dead and knock the wind outta you under 300 yards – anything over and you’d probably be maneuvering to outflank and/or calling in support anyhow. Even if that weren’t the case…you have your soldiers with the sharpshooter varaient who can be called out to snipe. And if it does come with the ability to upgrade to a 7.62 round with a bolt and barrel change than so much the better. Remember that a platoon operates as a team…(and they equip BASED ON THEIR MISSION) so you have soldiers with the standard version, soldiers with the sniper version, soldiers humping the grenade launcher and shotgun attachments and LM gunners – all fitted out before going out on mission. They all rely on one another as a unit. There is no rambo…and no one weapon that would be perfect for him. The mechanics of it are certainly FAR better than the m-16 (although I’m a HUGE fan of the m-14) with the ‘positive’ mechanics of a piston driven bolt action and forward gas release – this will make a giant difference no matter how clean your powder is. So as far as the ammo…its light, has good range and piercing ability and its cheap and abundant (which is a consideration…everything costs something) and will it get the job done? Seems like its doing it fine so far…I can’t believe a slightly larger round with knockdown power will make up for say, a poorly trained soldier being unable to work as a unit within his platoon. But then…opions are like…well, you know ;) J

  44. True, the 5.56×45 round is lethal but there have been many cases where soldiers have shot their enemy six or seven times in the chest with it and still haven’t put their target down. In some states it’s illegal to kill a deer with 5.56×45 as they feel it is inadequate. Now, the 7.62×51 is powerful but it’s a bit too heavy for troops to be running around with. The 6.8 SPC is a good inbetween round. More knock-down power along with similar 5.56×45 NATO trajectory. Of course if we really wanted to ensure that it was a one-shot-drop we could always employ APLP rounds. From what I’ve seen and heard, any shot to the torso and head will result in death. Limb shots will result in the loss of the limb and these were tested with 5.56 and 9mm APLP rounds. If they made a 6.8 APLP round it’d be like eating a hand grenade (slight exaggeration). If you don’t know what APLP (Armor Piercing Limited Penetration)rounds are they’re basically rounds that were developed to pierce armored targets but not over-penetrate them (friendlies on the other side and whatnot). The way it prevents itself from over-penetrating is by exploding/fragmenting inside something warm. Something warm like a human body. They conducted field tests in Iraq with them. In the report one soldier shot a terrorist in the buttocks and killed him instantly. They described the wound as ‘untreateable’. Seeing as there is a bunch of tiny fragments ripping through his internal organs it’d be near impossible to stop the bleeding. Multiple organ failure.

  45. Just for the record…i’d like to see em upgrade the rifle to 6.8mm standard. BUT it sure seems like the Brass has very little interest in doing so (mostly for monetary and political reasons to be sure) J

  46. *sigh* i read thru this whole posting hoping to find some more info about the xm8 and all i get is arguments about the caliber size. A) im not gonna throw my 2 cents in on that issue. B) everyone seems to have missed the point of the entire xm8 project. its not intended to be the next primary weapon for the american military or any other. its an interim weapon while the xm29 is finished. Then it will be issued only to airborn and non-frontline units that need a lighter weapon than the xm29 will certainly be. C) the works of the xm8 are the same as the BACK-UP close range weapon on the xm29, its not supposed to be the main kill factor. and no one can gripe bout the 20mm of HE goodness in the main gun on an xm29. well, mebe ya can… the world is full of idiots.

  47. umm….. wolfman, hate to brake your heart, but i belive the xm29 project was completly canceled. the weapons two parts were divided into two seprate induvidual programs, the xm8 and some fancy grenade launcher thingy. and one other point i just realized, the xm8 has a 12.5mm barrel, thats the same as the g36k right? the g36k is issued to german special forces and non front line troops, like our m4. the standard german army uses a g36 with a 20mm barrel like the m16. the xm8 only uses a 20mm barrel for sniping and SAW purposes. what im saying is will there be a full sized battle rifle version of the xm8 with a longer barrel????