Multi-Caliber AR's--Necessity or Useless Boondoggle?

[Spooky130]

I've had an LMT MRP since about 2004 or so... I have 2x 5.56 barrels and 1x 6.8 barrel. I imagine I have swapped the barrels 10 to 12 times in total over the period I've had the rifle. It is nice to have the capability but I hardly ever use it. The drawbacks are the initial cost, heavy profile LMT barrels, and the weight of the platform itself.

Spooky

[Tokarev]

I've had an LMT MRP since about 2004 or so... I have 2x 5.56 barrels and 1x 6.8 barrel. I imagine I have swapped the barrels 10 to 12 times in total over the period I've had the rifle. It is nice to have the capability but I hardly ever use it. The drawbacks are the initial cost, heavy profile LMT barrels, and the weight of the platform itself.

Spooky

I like the MRP and think it's a simple approach to a unique problem. Not only does it allow the shooter to switch to different calibers but it also allows the shooter to choose between gas and gas piston without changing anything other than the barrel and bolt carrier.

But, while the idea looks good on paper, I just don't see it as being a very realistic feature.

[Spooky130]

I like the MRP and think it's a simple approach to a unique problem. Not only does it allow the shooter to switch to different calibers but it also allows the shooter to choose between gas and gas piston without changing anything other than the barrel and bolt carrier.

But, while the idea looks good on paper, I just don't see it as being a very realistic feature.

The one catch is you have to have the CQB length chasis and not the rifle length one for piston use...

Spooky

[Crow Hunter]

If it is included as part of the basic design in which there is no increased cost or increase in weight/complexity from a caliber specific firearm, I don't have a problem with it.

Otherwise, no.

I went down this path once before. I had a New England Firearms rifle that I had a .243 light profile barrel, .223 heavy barrel, 45-70 barrel w/ open sights, 12, 20 and .410 shotgun barrels for. All it took was a phillips screw driver to undo the forearm and voila, open the action, put the other barrel in place, close the action and put the forearm back on.

It sounded much cooler than it actually was. It was always in the configuration that I didn't want at the time I went to use it. After having it a while, I decided that I would rather just have individual guns than a switch barrel gun.

I sold it to my brother who thought it was a cool idea, until he had it a while and he sold it to someone else. That thing has probably been all over the state by now.

I think is an idea that sounds much better on paper than it is in reality.

[maximus83]

The multi thing sounds good on paper. As a guy who deals with many aspects of modularity in my job, it's always appealing to see a well thought-out design that makes a product modular and multi-functional.

However, it seems like others have said it well. The test of a design is whether the modularity really gains you anything that you NEED under ordinary usage conditions. Doesn't seem that hard to pop a couple of pins and throw on a new upper--preferably with its own dedicated optic, already zeroed. There may be a few special cases where the multi setup is useful, so I'm hesitant to say it's completely worthless. But I know for sure that I don't need it, and I doubt that most shooters will find it to be that much of an advantage over just getting another upper.

[Tokarev]

I see a number of positive votes for the QD barrel in the poll but most of the replies have been generally against the idea.

If you like the idea of a QD barrel on an AR, please express your thoughts.

[cl2]

I see a number of positive votes for the QD barrel in the poll but most of the replies have been generally against the idea.

If you like the idea of a QD barrel on an AR, please express your thoughts.

I think its a good idea, but not worth any additional cost. A system like this will probably only really take off in the commercial market. It must therefore not cost a great deal more up front than a premium AR and conversions must be cheaper than a new upper (w/o optics). This will allow a shooter to shoot low cost training ammo (like 5.45) and switch to their main cartridge when the situation arises while using the same chasis/receiver.

[jasonusvi]

I like the MRP and think it's a simple approach to a unique problem. Not only does it allow the shooter to switch to different calibers but it also allows the shooter to choose between gas and gas piston without changing anything other than the barrel and bolt carrier.

But, while the idea looks good on paper, I just don't see it as being a very realistic feature.

Totally realistic to me. I've got 10 barrels for my 2 MRPs and 1 MWS. You can match up optics to barrels or record adjustments for a zero set on one barrel for a switch to another barrel. Id guess I have saved thousands of dollars not having to invest in 10 seperate uppers. I picked up my 12.5" 6.8 used with a vltor hider and 6.8 bolt for under $300 for another sweet option. Adding Noveske 6.5 Creedmoor option to my LMT MWS for little over $700 couldn't be done for less. 22lr, 300BLK, 2 - 6.8s, 3 - 5.56 (1 a 12" piston), 1 - 308, 1- 6.5CM, 1 - 6.5PCC. Just sold 14.5" with pinned FSC556 for $275 to offset the 6.5PCC. Try selling a barrel with a pinned comp out of a standard upper.

[Tokarev]

Totally realistic to me. I've got 10 barrels for my 2 MRPs and 1 MWS. You can match up optics to barrels or record adjustments for a zero set on one barrel for a switch to another barrel. Id guess I have saved thousands of dollars not having to invest in 10 seperate uppers. I picked up my 12.5" 6.8 used with a vltor hider and 6.8 bolt for under $300 for another sweet option. Adding Noveske 6.5 Creedmoor option to my LMT MWS for little over $700 couldn't be done for less.

Does the LMT system return to zero when you remove and re-install any of the barrels? Surely there's some POI shift?

I have a 16" piston LMT but don't make a habit of taking the barrel on and off and this feature wasn't one of the driving factors in my decision to go with this rifle.

I like the idea of the dedicated 22LR barrel. Any reliability issues with it? How's it shoot?

[MistWolf]

Quick change systems have been offered to the shooting public in one form or another since I can remember. None are popular enough to become "mainstream"

What will the ability to switch from say, 5.56 to 6.8 give you that switching to the right type of 5.56 ammo won't? (Granted, in the military, ammo choices are limited, but so is caliber)