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.

Comments

  1. it is my humble opinion,such as it is with my knowledge as an enthusiast.that we may better be served by this new rifle,as it is from what iv’e gleaned from recent information to be capable of caliber conversion by simply swapping out barrels.this would,in effect,negate any argument as to the ‘right round’for the job.the operator in the field can,if desired,tailor the weapon to his mission requirements.if he needs a weapon that can reach out to open field ranges at or exceeding 400 meters,drop in a 20 inch barrel.conversely for cqb or mout operations,go with a 9 to 12 inch tube to negotiate the tight confines of that environment.irregardless,it will all depend on what happens in the’real’world when(if) our operators get this new rifle in hand and take it into harms way.all the technological advances will amount to nothing if the thing doesn’t go ‘bang’ when the trigger gets squeezed or the round chambered doesn’t drop the tango the first time.my concern is that for our operators in the field,they deserve a weapon which will get the job done and function flawlessly to boot.heckler and koch has a good idea,our guys deserve the best.to quote h&k,in a world of compromise,some don’t,lets hope this philosophy holds true with the developement of the xm8.

  2. That picture is NOT an M8. If you want one, let me know. I am a business development guy for Brashear LP in Pittsburgh. We are making the sight for the XM25 (the 25mm adjunct to the XM8). The sight, known as the XM104, has uncooled thermal sensing, a ballistic computer for determining a corrected aimpoint and a day TV. If you need any more info, please let me know.

  3. I have read all the posts and still do not understand how the gas system works without introducing the gas from the round into a piston. Can anyone help?

  4. Well i sure hope they come out with a larger caliber…….. or maybe some expanding ammunition that is legal for combat……. because that stupid 5.56 with military combat ammunition doesnt do the job unless you hit an absolutly vital area of the body…. SEMPER FI

  5. a quick note on that ………. i dont want to teen age queen….. i just want my M-14….. SEMPER FI

  6. The XM8 just looks flimsy compared to the M-16. Why is the U.S. government spending millions researching a completely new line of assault rifles when we could just improve the current system? Why don’t we institute the 7.62 round?

  7. For those out there who know various systems of rifles in the past, the gas-piston system for the XM8 is the most conveniant and most effective system there is. It is NOT a new development. It has been used with the famous Kalashnikov design(AK-47) for more than 60 years. I’m just exited that our military has finally taken a step to advance our line of weaponry to this new rifle. I have shot both the M-16 and AK-47/74 for many years. Anyone who has used them both as long as I have will know their capabilites. The M16 is one of the best rifles and I love it. The design of this rifle is the answer to most of the problems with any kind of rifle in the past. It’s really a matter of common sense. Why would you want a rifle that doesn’t fuction when you want it to? Why not have the most powerful and effective cartridge possible while having the most lightweight? The military needs to ‘get on their feet’ and get this to all of our troops ASAP to save more American lives!

  8. I use to work for the coranor’s office in riverside,ca. and i’ve seen the damage of 7.62 and the damage of a 5.56. give the troops the 7.62 and they WIll stop any and all.

  9. Why don’t we institute the 7.62 round?’ recoil is one big reason. Any new general purpose cartridge chosen must not be too powerful to spook the average trooper, and thus screw up their aim. Full automatic was also a problem for the m-14, too much recoil to handle well. 7.62×39 is better, but lacks accuracy. I would likely favor the 6.5×45 Grendel to replace the 7.62×51; though I am not sure if the Grendel works well enough for other purposes yet.

  10. Uparm the caliber to 6.8mm SPC due to the deficiency of 5.56mm in the M-4 Carbine. Soldiers need range and ‘knock-down’ power to kill the enemy. 5.56mm with the shorter barrel doesn’t do the job.

  11. The 6.8 would be a probably replacement. The idea piece that would go along with whatever the brass decides to use would be a well qualified shooter using the M-14, that round can reach and touch someone. Why do we need to spend millions of our hard earned bucks searching in vain for a miracle firearm? The Tommy gun, which was a wonderful piece but expensive to manufacture was replaced by the Grease Gun, going price during WW2 was 15 bucks, nothing sophisticated about that, with some minor improvements this could be used for close operations. Commonality of ammo, why for example you already have the 9mm for that pop gun that is why many police departments are going back to the old and trusted 45 ACP. We need common sense, not out of control spending on toys.

  12. SL Thompson: I don’t disagree with you on the submachinegun idea. I don’t really understand why a 9mm or .45 SMG wouldn’t be a good solution for many. It’s certainly not a new assault rifle, but I think it would have a place for sure.

  13. It’s an odd looking rifle, in that it looks designed on an autocad for maximum angularness, and not for soldier comfort. I think it will be hard to machine some parts of it, and that will make it expensive, like the Thompson, which someone mentioned earlier. The US is not moving to a mid-range cartridge, regardless of the possible benefits of this at close or long range. In fact, it appears they are now further attempting to limit the ammunition’s weight by creating a new composite plastic/brass casing for the XM8, and I think you would see this ammunition (if successful) eventually being used for all service rifles and light machineguns. I might go with a smaller caseing all-together, using an existing technology. I think of in similar terms to the design benefits the Germans got from going to the 8mm Kurtz for the MP44 rifle, or our own switch from the 30.06 to 7.62 Nato. Two of the benefits of this are a shorter action stroke, and less ammunition weight. The main negative effect of this move now is that there will be a much quicker stress pressure placed on the action and the rifle breech when it fires. And like the Germans, you now have two sets of ammunition that are not interchangable between rifles. Is this rifle a good replacement? What does it do? I think the main thing that the US Army is trying to accomplish with this weapon is to collapse the SAW, the M16, and the M4 into one package. They want to incorporate into it an improved sighting system (awesome and about time). This may put the long-range ‘Garandness’ back into the US battle rifle. It will also give the US soldier in the desert a desirable long range accuracy edge over an enemy armed with an AK 47. They want the stock to be able to be quickly collapsed. Ever try to get a M16 out of the turret of an M1A tank? It is a problem. The M16 is also longer than the frame of an average house doorway, meaning you cannot approach and move through a door with it in a perpendicular ‘strafe’ movement. Look for the picture of the US Marine in Iraq with the Russian WW2-era PPSH if you want an idea of what an ideal building assault weapon design is. Being able to switch out the barrels on a light machine gun is a must. The lighter you can make the machinegun, the better it will be, until you reach a point where the barrel jumps up like crazy and shot control is the problem. I don’t think a light weapon can be made to replace a locked-down support machinegun. From my experience with the SAW, it jumps around a bit, but the volume of fire makes up for it. The true use of the SAW is to provide a continuous volume of fire to supress a position using linked ammunition. I think you may be able to do this with a special 50-round clip. and I think one of the advantages of the Assault Rifle has always been that it is designed to be able to supress with volume of fire, and let infantry get away from their squad supported machine guns and suppress objectives, or kill the enemy with volume of fire, as necessary. They are having some problems with this weapon. The plastic areas around the reciever and the grip are repoted to melt when the weapon is fired for long periods on automatic. Any weapon, I think, should be designed to be comfortable. I’m not sure if this one is. It should also not repeat problems with other weapon systems, such as the British SA80. The main problem I see in any weapon (it doesn’t necessarily have to be a bullpup) is the ratio of weapon behind, and in front of the trigger guard and pistol grip. For every inch one way or the other, as someone pointed out, a soldier must expose more or less of their own body to fire around a corner. So with a small barrel, you get a weight savings, but you also get a soldier who must lean out along the axis of the rifle more and more to aim and take a shot. The gas system on the XM8, as people have pointed out earlier, is designed to use an intermediary push rod to piston stroke against the bolt instead of using direct gas pressure to unlock the bolt and throw it back. The problems with direct gas, as pointed out earlier, are that you get accelerant (powder) residue inside of your reciever and bolt carrier group in the M16 and M4, and that this invariably gunks it up and makes it not fire after about 60 shots. Another problem with the M16 and M4 is that the close tolerances of the bolt group and reciever causes any dust or dirt, or the heated, swelling metal of the bolt to tend to make it stick and become unoperable, usually when you really need it to operate. This is not a problem in most Russian made assault weapons. The idea of the seperate piston rod is not new, and was used I think in the Gewher 42 and MP 44, and was probably copied somewhat into the AK 47, though other parts of this weapon are quite different. The great advantage, besides having no direct ammunition residue, is that now the barrel can now be quickly seperated as an independent group from the rest of the rifle and replaced, the gas-bolt push rod end acting as a place of seperation between the reciever and the front end ofthe rifle. You cannot do this currently on a M16 or M4, but you can do it on a SAW becuause it uses a gas piston. My ideal weapon would have a long, desert barrel, and give the operator an improved sight picture that would give them limited 2x magnification out to 350 meters. It would allow them to kill people armed with AK’s at that range, while exposing as little of themselves as possible, while the enemy exposes himself to shoot his AK. My soldier would change the barrel and the sight out to make it into a smaller, city-assault weapon when needed, and put in a 50-round clip. I would probably make the bolt carrier group rotatable, in the open bolt position, to allow ejection from either the left or the right port. And with those two ports, you could easily change out the bolt and the barrel, and it could then fire linked ammunition throught the dual ports across the action like the FG42. I’m not sure this is what they have here, but this is what I think they want. I would also go for a forward stock that had a laser rf and sight, and had a recessed grove in the lower stock for the fingers. This is something even an SKS has, and it is better than a semi-round piece of hard plastic. The front stock could also used and integrated, fold-down grip, as you see a lot of fixed front grips on the M16s and M4s in pictures from Iraq. In my time in the military, I never saw the ‘carrying handle’ on one of these rifles ever used as a carrying handle. One should be attached to the barrel of the machinegun variant as it is on the current M60. If a handle/sight mount is used, it should be smaller, and not bigger. The XM8 is made all awkward by the one it has now. The handle should aid in stowage in a HUMVEE or other vehicles. There should be imporoved sling mounts on it too. That is my take on this weapon.

  14. It’s an odd looking rifle, in that it looks designed on an autocad for maximum angularness, and not for soldier comfort. I think it will be hard to machine some parts of it, and that will make it expensive, like the Thompson, which someone mentioned earlier. The US is not moving to a mid-range cartridge, regardless of the possible benefits of this at close or long range. In fact, it appears they are now further attempting to limit the ammunition’s weight by creating a new composite plastic/brass casing for the XM8, and I think you would see this ammunition (if successful) eventually being used for all service rifles and light machineguns. I might go with a shorter caseing all-together, using an existing technology. I think of in similar terms to the design benefits the Germans got from going to the 8mm Kurtz for the MP44 rifle, or our own switch from the 30.06 to 7.62 Nato. Two of the benefits of this are a shorter action stroke, and less ammunition weight. The main negative effect of this move now is that there will be a much quicker stress pressure placed on the action and the rifle breech when it fires. And like the Germans, you now have two sets of ammunition that are not interchangable between rifles. Is this rifle a good replacement? What does it do? I think the main thing that the US Army is trying to accomplish with this weapon is to collapse the SAW, the M16, and the M4 into one package. They want to incorporate into it an improved sighting system (awesome and about time). This may put the long-range ‘Garandness’ back into the US battle rifle. It will also give the US soldier in the desert a desirable long range accuracy edge over an enemy armed with an AK 47. They want the stock to be able to be quickly collapsed. Ever try to get a M16 out of the turret of an M1A tank? It is a problem. The M16 is also longer than the frame of an average house doorway, meaning you cannot approach and move through a door with it in a perpendicular ‘strafe’ movement. Look for the picture of the US Marine in Iraq with the Russian WW2-era PPSH if you want an idea of what an ideal building assault weapon design is. Being able to switch out the barrels on a light machine gun is a must. The lighter you can make the machinegun, the better it will be, until you reach a point where the barrel jumps up like crazy and shot control is the problem. I don’t think a light weapon can be made to replace a locked-down support machinegun. From my experience with the SAW, it jumps around a bit, but the volume of fire makes up for it. The true use of the SAW is to provide a continuous volume of fire to supress a position using linked ammunition. I think you may be able to do this with a special 50-round clip and a clean, reliable bolt. I think one of the advantages of the Assault Rifle has always been that it is designed to be able to supress with volume of fire, and let infantry get away from their squad supported machine guns and suppress objectives, or kill the enemy with a heavy volume of fire, as necessary. They are having some problems with this weapon. The plastic areas around the reciever and the grip are repoted to melt when the weapon is fired for long periods on automatic. Any weapon, I think, should be designed to be comfortable. I’m not sure if this one is. It should also not repeat problems with other weapon systems, such as the British SA80. The main problem I see in any weapon (it doesn’t necessarily have to be a bullpup design like the SA80) is the ratio of weapon legnth behind, and in front of the trigger guard and pistol grip. For every inch one way or the other, as someone pointed out to me, a soldier must expose more or less of their own body to fire around a corner. So with a small barrel, you get a weight savings, but you also get a soldier who must lean out along the axis of the rifle more and more to aim and take a shot. The gas system on the XM8, as people have pointed out, is designed to use an intermediary push rod to piston stroke against the bolt instead of using direct gas pressure to unlock the bolt and throw it back. The problems with direct gas, as pointed out earlier, are that you get accelerant (powder) residue inside of your reciever and bolt carrier group in the M16 and M4, and that this invariably gunks it up and makes it not fire after about 60 shots. Another problem with the M16 and M4 is that the close tolerances of the bolt group and reciever cause dust or dirt, or the heated, swelling metal of the bolt to tend to make it jam up and become unoperable, usually when you really need it to operate. This is not a problem in most Russian made assault weapons. It is certainly a problem with any weapon used for direct supression and volume of fire advantage. The idea of the seperate piston rod is not new, and was used I think in the Gewher 42 and cetainly in the MP 44, and was probably copied somewhat and intergrated from there into the AK 47, though other parts of these two weapons are quite different. A great advantage, besides having no direct ammunition residue, is that now the barrel can be quickly seperated as an independent group from the rest of the rifle and replaced, the gas-bolt push rod end now acta as a place of seperation between the reciever and the front end ofthe rifle. You cannot do this currently on a M16 or M4, but you can do it on a SAW becuause it uses a gas piston. My ideal weapon would have a long, desert-woodland barrel, and give the operator an improved sight picture that would give them limited 2x magnification out to 350 meters. It would allow them to kill people armed with AK’s at that range, while exposing as little of themselves as possible, while the enemy exposes himself to shoot off his AK ineffectively. The soldier would change out the barrel and the sight on the weapon to make it into a smaller, city-assault rifle when needed, and put in a 50-round clip. I would probably make the bolt carrier group rotatable in the open bolt position, to allow ejection from either the left or the right port of the rifle. There are a number of ways to do this, and it eliminates a lot of problems with left-handed shooters and bullpup design. And with those two ports, you could easily change out the bolt and the barrel, and it could then fire linked ammunition throught the dual ports across the action like the FG42 or SAW. I’m not sure this is what they have here but this is what I think they want. I would also go for a forward stock that had a laser r.f. or laser sight, and had a recessed grove in the lower stock for the fingers. This is something even an SKS has, and it is better than a semi-round piece of hard plastic to try and grab onto with a glove. The front stock could also used and integrated, fold-down grip, as you see a lot of fixed front grips on the M16s and M4s in pictures from Iraq. In my time in the military, I never saw the ‘carrying handle’ on one of these rifles ever used as a carrying handle. One could be attached to the barrel of the machinegun variant as it is on the current M60. If a handle/sight mount is used, it should be smaller, and not bigger. The XM8 is made awkward to stow and grab onto by the one it has now. The handle should aid in stowage in a HUMVEE or other vehicles. There should be imporoved sling mounts on it too. That is my take on this weapon.

  15. hi im intrested in the m8, i know its old news now, well not really… but does any one have a video clip of it firing, if you do can you please tell me the web site of the … well site lol thanks!! o yeah and i think that the m4 and m16 will always be gr8 but the m8 does look cool 🙂

  16. I think that a new infantry weapon is a good idea for the US military. The 5.56mm NATO was and is a decent round but the ball ammo doesn’t stop a person as well as say a 7.62X39mm. The 5.56mm is only effective at 400 meters or less and at any greater range then 200 meters you just hope that you hit something. The new ideas of the XM8 and other ‘X’ rifles is a little on track but you need to think all so that the world is moving in to urban areas where you run in to a lot of innocent people in the way. Soliders have to remember that civilans aren’t who we are out to kill. Todays urban combat zones don’t have defined lines like they did in WW1, WW2, and Korea. You have insurgents in every possible place and coming at you from every possible angle. A short barreled rifle is a good idea for urban combat or ‘CQB.’ However you can’t use a weapon that has a short barrel at long distances. So I propose a weapon that allows the distance and the capability of the 7.62mm’s (i.e. M-14)but still allows for you to change from a longer barrel and hotter round in the fields and deserts, to a different barrel and round that allow for ‘CQB.’ The shorter barrel with the hotter round allow for a better penetrating wound along with not necessarily allowing the round to travel through a wall and in to the next hut (i.e. Frangable Rounds). A weapon that can fire these rounds for ‘CQB’ is ideal for urban combat. Its only when your on your way in to town that you should worry about range of a round that is fired. So XM8 is an ideal platform for both long range and close quaters combat. But hey thats just my opinion.

  17. This new, improved 5.56 looks like a finely designed weapon, but the wrong caliber. It should be 6.5 or 6.8. After all, the most successful cartridge of modern time was the 7mm German Mauser. As for the beefed up 22 we call 5.56. A nice popgun, but did we not learn anything from all our wars about stopping power. If not for the Philippines we’d never have enjoyed the Colt .45 auto.

  18. XM8 design changed from good to worse and the problem is even though alot of $ was invested into the weapon, it was hoped that it would be cheap in the long run as you wouldnt have to have SAW or SDS weapons. Alot of money was invested but the XM8 has been cancelled because in testing it melted due to high temperature in hot enviroments and continous fire. Personaly I would have improved the M16 or G36. HK built the HK416, which can be easily swapped to 5.56-7.62 fires even when placed in salt water and sand plus its a very similier design to the M16/M4. NATO should really invest together with is fire arms companies and build an ultimate infantry weapon, which mets all the armed forces requirements in NATO.