Due to popular demand: The XM8 Assault Rifle

According to my referrer stats, the most popular search that brings readers to MO is “xm8”. Since I’ve only mentioned the XM8 once, I guess maybe a little more info is in order.

The XM8 (which will become M8 when it goes operational) is the planned replacement for the current assault weapons in the US military, the M16 and the M4.

For some time, the Army has been developing the Objective Individual Combat Weapon (OIWC). Designated the XM29, it was going to be a combination of a 5.56mm assault rifle and a 20mm “smart grenade” launcher. The grenade launcher fired air-bursting explosive rounds up to half a mile that could be used to attack enemy troops behind cover or around corners. Additionally, the sights on the XM29 were going to be high-tech video units with magnification, and thermal imager, laser range finder, electronic compass, and a ballistic computer used to program the grenades. Although it performed quite well in tests, developers were not able to get the weapon down to the weight requirements and there were concerns about its ruggedness. The XM29 program is currently on hold and in danger of being scrapped completely. (If they’d just watch Aliens they’d see just how valuable these might be.)

However, while the fate of the XM29 is being debated, two seperate but related programs, the XM8 assault rifle and the XM25 grenade launcher, are going ahead. In fact, the development of the XM8 has been accelerated and 200 samples for heavy testing are due this fall.

The Test and Evaluation Command will use two types of testing — developmental and operational — to ascertain the XM8s viability.

Developmental testing is similar to what Consumer Reports magazine would do, [project manager Lt. Col. Matthew] Clarke explained.

“We will super-cool the weapon. We will fire it to failure to see what breaks,” Clarke explained. “We’ll drop it, we’ll put chemicals on it to see how it reacts. That will provide the hard data to build a case for reliability, availability and maintainability, or not.”

At the same time, testers will bring soldiers into the loop for limited operational testing.

“We will get soldiers to use the weapons in harsh conditions and get their opinions,” Clarke continued.

The XM8 is based on the asault rifle half of the XM29 combo system. It will fire a standard NATO 5.56 round and is based on the very successful H-K G36 assault rifle.

The XM8 is a modular weapon, with three different barrel lengths available: a standard short barrel for normal use, a longer, heavier barrel for use as a light machinegun, and a very short barrel for use by commando-types and vehicle crews. Given recent reports out of Iraq, I think the tankers will be grateful. The standard barrel will give the weapon a size similar to the current M4 carbine, while shaving about 20% off the weight due to material advances developed by the OIWC program. This should be a welcome development to our troops, who are weighted down with all sorts of equipment and protective gear, and have been wanting a shorter weapon than the M16 for street fighting. In Baghdad, some US troops opted to use captured AK-47s.

There will also be a number of other options for the stock and attachments. This will allow units to equip on the fly for the environment that they expect to do battle in and (hopefully) have the right weapon for the job at hand. Also, the integrated sight will include a number of options currently available only by adding additional equipment to M4s and M16, saving weight, cost, and training requirements. There is discussion about eliminating the three-round burst mode currently used on the M16, as well. 3-round mode was added in the 1980s when it was discovered that most riflemen were not particularly effective when using full-auto. Recent analysis suggests that additional training in the use of full-auto will get the same results, and it will allow the governor that creates the 3-round burst to be left off the weapon, reducing cost, weight, and the number of things that can break.

There is a lot of debate over the 5.56mm round. Many troops question its stopping power, especially when fired from shorter barrels like the M4 or the proposed standard barrel of the XM8. While perhaps not as much of an issue in the narrow streets and alleys of Baghdad and Tikrit, it could become an major issue in a more open setting, like the hills and mountains of North Korea. In fact, a number of reports from Afghanistan indicate that special forces units using M4 carbines were unable to effectively engage forces at times due to the range and power limitations of the shorter barrels. Perhaps an option would be to include a fourth barrel length, longer than standard but not “machinegun weight”. Another option would be to just keep one or two men in each squad with M16s as “sharpshooters”. This would dilute the advantage of using a universal infantry weapon, however. Maybe some M8s could be modified to fire the 7.62mm round, as some M16s have been. This would increase the firepower of the weapon, but, again, it would negate the commonality that the XM8 hopes to bring to our ground forces. Here is a page that discusses in depth the concerns with the 5.56 round, shorter barrels, and the new assault rifles.

I’m concerned that a lot of work is going into a weapon that is only a slight improvement over our current systems. Instead of throwing out over 40 years of experience with the M16 for incremental improvements in an entirely new gun system, maybe we should work to make those improvements to our current guns. I’m certainly no expert, but it seems to me that we’re investing an awful lot of time and money into this and not getting a lot of bang for the buck. At the same time, I see good value in some of the ideas the XM8 brings to the table, and am quite interested to see how it performs in tests and with the troops.

On the other hand, the XM25 25mm grenade launcher, incorporating the “smart” features of the grenade launcher on the XM29, looks like it could be the revolutionary weapon that changes the battlefield for the foot soldier. Maybe we should accelerate that program instead.