Modular (multi caliber) rifles

[Trooper]

Starting to see a bunch of modular rifles on the market. most have gas piston systems such that it is easy to swap barrels (thus calibers).

Beretta is putting the ARX100 on the market. It has both a 5.56x45 barrel and a .300 BLK barrel available. http://www.americanrifleman.org/blogs/beretta-arx-100/

Faxon Firearms (http://www.faxonfirearms.com) has introduced the ARAK-21 upper in 5.56 and 300 BLK.

The IWI Travor bullpup is also capable of being a modular rifle as its barrel is easily swapped out. http://www.iwi.us/travor

And Lewis Machine Tools (http://www.lmt.com) has a AR10 system that is modular.

[LRRPF52]

The LMT MRP has always had a Quick Barrel Change feature.

The Steyr AUG has a quick barrel change feature without tools.



The MGI Hydra Mk 15 has a tool-less quick barrel change feature, as well as a modular magwell so it can take AK, AK74, Grease Gun, Glock, and even M14 mags for the .308 version.



The SCAR is supposed to be modular with a simple quick barrel change system.

The Magpul Masada, which became the Bushmaster & Remington ACR has a concealed barrel nut wrench attached to the barrel nut under the handguard, so is a tool-less.

Interestingly enough, the Remington Model 8 sporting rifle from the early 1900's, and later the Model 81, had a break-down feature that the Masada seems to be patterned after. The locking lever compensates for wear on the threads, so the rifles never become loose.

[LRRPF52]

MGI with AK magwell:



SCAR-16:



Magpul Masada:



LMT MRP Variants:

[mongoosesnipe]

Easiest set up is probably an ar15 with multiple uppers pop two pins and bam a whole new gun

[bwaites]

Easiest set up is probably an ar15 with multiple uppers pop two pins and bam a whole new gun

My lower can become a 5.56, 6.5, .22, and Beowulf in about 15 seconds per change. I can't figure out why everyone thinks that swap barrels are so cool?

[jeff556]

Bill, I just can't do it. When I have an upper sitting around ready to "swap in" the compulsion to build / buy a lower becomes overwhelming.

[Trooper]

My lower can become a 5.56, 6.5, .22, and Beowulf in about 15 seconds per change. I can't figure out why everyone thinks that swap barrels are so cool?

Good enough for a civilian. But not for military. Ever tried backpacking several uppers? You need a short barrel (10 to 14 inches) for inside vehicles, a 16 inch barrel for patrol and a long (20") for DMR. Plus if you do special work then you need various calibers. For example the 300 BLK is good for suppressed work or for in close work taking out guards and such. Plus you may need to be able to use captured ammo (7.62x39) if you are in a long fire fire.

[bwaites]

Good enough for a civilian. But not for military. Ever tried backpacking several uppers? You need a short barrel (10 to 14 inches) for inside vehicles, a 16 inch barrel for patrol and a long (20") for DMR. Plus if you do special work then you need various calibers. For example the 300 BLK is good for suppressed work or for in close work taking out guards and such. Plus you may need to be able to use captured ammo (7.62x39) if you are in a long fire fire.

I haven't, but has ANY ground soldier EVER done that? They would have to carry barrels and various ammo as well. That makes NO sense. So figure the load out. Maybe 100 rounds of 330 BLK for suppressed work, then 100 rounds for DMR work, then 300 rounds for patrol. That's 500 rounds, and you really don't have enough of any one to be effective at any of the jobs.

Not buying that as a reason for swappable barrels.

I appreciate the theory, I just don't think anyone at the mil.dot level would buy into it.

[LRRPF52]

Good enough for a civilian. But not for military. Ever tried backpacking several uppers? You need a short barrel (10 to 14 inches) for inside vehicles, a 16 inch barrel for patrol and a long (20") for DMR. Plus if you do special work then you need various calibers. For example the 300 BLK is good for suppressed work or for in close work taking out guards and such. Plus you may need to be able to use captured ammo (7.62x39) if you are in a long fire fire.

Sounds like you need a tactical barrel quiver, with color-coded barrels including night markings for when we prep men, weapons, and equipment in the ORP before slaying hood rats in the ghetto suppressed. I can just see the guys now guessing how many clicks they need to adjust for each different barrel as they squint in the night down at their turrets. Would you suggest leaving the different caliber mags at the ORP with the rucks?

Ain't no way that scenario is feasible. It would make an awesome sequence in a James Bond movie, especially if he could whip out a 7.62x39 barrel and start picking up enemy mags from the wake of carcasses left in his path, but a major NO-GO in the world I'm familiar with. We had a hard enough time getting guys to bring the mission essential equipment in prep for actions on the objective as it was. Trying to re-configure weapons with a modular, quick-change barrel system sounds like a nightmare to me personally, although I used to think about the feasibility of this long ago.

In a UW setting, the capability makes a little more sense, as long as current capabilities weren't sacrificed, but it would still be done in a more UW armorer role in a secure area. For example, you deploy with 5.56 NATO configured carbines, but have the capability of switching to the local logistics scheme once linked up with indigs for a while. You would take the time to re-configure and zero weapons on a field-expedient range, and make sure the locally-available mags actually run in the guns before trusting them. There's hardly enough time to sleep as it is in those scenarios, so any range time is a luxury at that point, if even possible in the signature limitations of the AO.

[mongoosesnipe]

Good enough for a civilian. But not for military. Ever tried backpacking several uppers? You need a short barrel (10 to 14 inches) for inside vehicles, a 16 inch barrel for patrol and a long (20") for DMR. Plus if you do special work then you need various calibers. For example the 300 BLK is good for suppressed work or for in close work taking out guards and such. Plus you may need to be able to use captured ammo (7.62x39) if you are in a long fire fire.

A3 upper receiver weighs 7oz add a float tube to the mix and round that up to a pound added over just a barrel seems petty light in order to not have to worry about loosing a zero.... And if you have managed to get into such an unsupported firefight that you have exhausted all of your ammo wouldn't it be easier pick up a captured rile to use captured ammo in rather than take a time out from the firefight to reconfigure your rifle

[Trooper]

Sounds like you need a tactical barrel quiver, with color-coded barrels including night markings for when we prep men, weapons, and equipment in the ORP before slaying hood rats in the ghetto suppressed. I can just see the guys now guessing how many clicks they need to adjust for each different barrel as they squint in the night down at their turrets. Would you suggest leaving the different caliber mags at the ORP with the rucks?

Ain't no way that scenario is feasible. It would make an awesome sequence in a James Bond movie, especially if he could whip out a 7.62x39 barrel and start picking up enemy mags from the wake of carcasses left in his path, but a major NO-GO in the world I'm familiar with. We had a hard enough time getting guys to bring the mission essential equipment in prep for actions on the objective as it was. Trying to re-configure weapons with a modular, quick-change barrel system sounds like a nightmare to me personally, although I used to think about the feasibility of this long ago.

In a UW setting, the capability makes a little more sense, as long as current capabilities weren't sacrificed, but it would still be done in a more UW armorer role in a secure area. For example, you deploy with 5.56 NATO configured carbines, but have the capability of switching to the local logistics scheme once linked up with indigs for a while. You would take the time to re-configure and zero weapons on a field-expedient range, and make sure the locally-available mags actually run in the guns before trusting them. There's hardly enough time to sleep as it is in those scenarios, so any range time is a luxury at that point, if even possible in the signature limitations of the AO.

The biggest problem is transitioning from a vehicle to on foot. A vehicle gun requires a very short barrel. Even fighting from an APC is not easy with our current M4s. The UK bullpup does a better job. The other problem is that often units do not have an armor. More likely just some extra duty function for a Joe. Thus anything major (like a barrel replacement on an upper) is sent off for depot level repair.

The piston system does allow for more flexibility over our current system. But then I see the M16/M4 as a poor design that was over engineered compared to the FAL or the AK family. In the past, the M14 was a good rifle, for WW2. Had they gone ahead with an M1 that had less wood and a BAR mag, it would have been a generational gun. During the '50s we needed to have listened to the Brits and gone with the FAL and the .280 British. We seem to be working from the past instead of designing for the future.

[LRRPF52]

The biggest problem is transitioning from a vehicle to on foot. A vehicle gun requires a very short barrel. Even fighting from an APC is not easy with our current M4s. The UK bullpup does a better job. The other problem is that often units do not have an armor. More likely just some extra duty function for a Joe. Thus anything major (like a barrel replacement on an upper) is sent off for depot level repair.

Some entry-level guys in Ranger Regiment I have discussed this with like the folding stock feature of the SCAR for working out of vehicles (they broke all the stocks on their SCAR-L's within a week), but I don't see it as that big of an issue since training is where the main focus should be for vehicle work. I run courses where we do a lot of shooting from within small sedans, and the M4 with 14.5" barrel works fine, although we do tend to prefer the 11.5" guns for those drills. There is no dimensional advantage to an L85 over an M4 in a vehicle, other than barrel length within the same length profile of the weapons.

There's a lot more space in a HMMWV or MRAP than a tiny Euro sedan as well, and I don't think anyone would realistically propose having a 10.5" barrel in their blaster in the car, then take a time-out once they dismount the trucks/APC's to drop-in a longer barrel. No way that will happen, even in a very small PSD or Diplomatic Security Detail organization.

I'm wondering how a Chain of Command gets away with not having an armorer. The systems that allow easier barrel change do make a lot of sense at the armorer level. The Brits are using the LMT L129A1 system (LMT 7.62 MRP) in the DM role successfully, but it is a pig for weight because of the barrel diameter at the shank.

The piston system does allow for more flexibility over our current system. But then I see the M16/M4 as a poor design that was over engineered compared to the FAL or the AK family. In the past, the M14 was a good rifle, for WW2. Had they gone ahead with an M1 that had less wood and a BAR mag, it would have been a generational gun. During the '50s we needed to have listened to the Brits and gone with the FAL and the .280 British. We seem to be working from the past instead of designing for the future.

The op-rod driven guns haven't proven to be worthwhile from both a reliability and weight standpoint. They are more costly to make in the AR15 frame, and for a QBC system, I don't see any advantages. There is only more weight per barrel, and a one-size-fits-all gas system length approach that doesn't do well with dwell time as the barrels get longer.

The AR15 family is an excellent design for a number of reasons. Units that have a choice as to what weapons they want to use almost always choose the M4 or Colt Commando variant, unless they are so prideful that they insist on carrying their nation's home-grown inferior rifle (HK G36 for example). The FAL and AK require more resources and training to maintain at the armorer level, and don't have the plug-and-play replacement part capability that the AR15 does. AK's are basically an expendable item as a whole, and often come broken/unserviceable from the factory, and FAL's will never have the inherent accuracy of the AR15, although they have better controls than the M14.

We've discussed the caliber issue at-length in the Mil/LE section, with a lot of history covered, to include the .276 Pedersen, .280 Enfield, 7mm Enfield, and so forth. As to the popularity of modular weapons, it is a growing trend that seems to be embraced more by the big Army logistics approach, but not one where the individual soldier is playing erector set with his or her blaster.