Does anyone here run a truly modular AR setup?

[Texas Heat]

So I've been reading and it seems that the gun was designed to be modular as in swap out barrel for different ammo options, different stock for pistol set up and so on. Now, everyone that I know just has multiple ARs. Does anyone here actually run a modular setup? What do you run? How many calibers can you get through the same gun with a barrel swap? I know the standard receiver won't work for larger calibers. What does a truly modular system look like?

 

[Younggun]

I don't think it was designed to be modular in the way you're thinking. More so to easily replace parts when needed.


That said, it just takes too long and sometimes I might want to have both setups shootable at the same time. Having multiple uppers for a lower is about as far as I would go.

 

[Texas Heat]

My next AR will probably be a home build and I am trying to get all my ideas on paper before purchasing things I don't need. I kind of like the idea of swapping a barrel to make a longer range weapon or shorter barrel for close quarter scenario. It seems like I'd get most bang for the buck that way but don't know how realistic these swaps would be.

 

[Younggun]

Best bet is to build 2 uppers and let them share a lower and BCG.

 

[grumper]

So I've been reading and it seems that the gun was designed to be modular as in swap out barrel for different ammo options, different stock for pistol set up and so on. Now, everyone that I know just has multiple ARs. Does anyone here actually run a modular setup? What do you run? How many calibers can you get through the same gun with a barrel swap? I know the standard receiver won't work for larger calibers. What does a truly modular system look like?

I do 5.56mm mag fed, 5.56mm belt fed, and 7.62 NATO on my Colt LE901. Could easily add 9mm mag fed, 9mm belt fed, and .22LR if I bought uppers for those too. It's easier to swap out entire uppers unless your AR has some kind of fancy quick detach barrel system.

Honestly haven't felt like messing with 9mm on the AR because the Uzi shoots much nicer in that caliber.

 

[easy rider]

If you wanted to change at the range, the upper would be an easier swap. You could use the same BCG easy enough.

Sent from my VS985 4G using Tapatalk

 

[DwnRange]

You could use the same BCG easy enough.

You have noted how easy it is to use the "same" BCG group twice now and while you are correct, it's easy - it is not wise to do so IMHO.

The "bolt" part of this equation interfaces directly with the barrel and whether mil-spec or not - there are variances and bolts always wear, just as the barrels they mate with do the same. YMMV, but I never swap bolts. A "new" upper (ie. barrel) always get a "new" bolt and this combination is never separated from each other in my rifles.

This makes for better accuracy and reliability in every AR15, AR10 platform I own - as the parts that were bought together, stay together. If I need to change a barrel due to round count then that bolt is completely disassembled and placed in my spare parts bin so I know it is a "used" part and never mixed with the "complete new bolts" - I never throw old parts away, as they are always saved and yes in a SHTF situation they would and could be utilized. In such a situation they'd be like gold or money in the bank.

Too many folks buy firearms, but never perceive of the need for spare parts - for what good is the best rifle if ya break a firing pin, extractor, ejector or bolt ya ain't got?

Swapping bolts around leads to broken bolts, which is not an issue today, but one day it might be.....

 

[rman]

I used to have 1 lower for my 6.75" 5.56 and my 10.5" 300BLK

But since I'm a gun lover, I build another lower for the 300BLK.

Same reason I probably wouldn't get a caliber conversion kit for my P320.... I would rather have another complete gun.

Only other thing I do is shoot 357sig out of my P229, but that's because .40 makes you bisexual.

 

[easy rider]

You have noted how easy it is to use the "same" BCG group twice now and while you are correct, it's easy - it is not wise to do so IMHO.

The "bolt" part of this equation interfaces directly with the barrel and whether mil-spec or not - there are variances and bolts always wear, just as the barrels they mate with do the same. YMMV, but I never swap bolts. A "new" upper (ie. barrel) always get a "new" bolt and this combination is never separated from each other in my rifles.

This makes for better accuracy and reliability in every AR15, AR10 platform I own - as the parts that were bought together, stay together. If I need to change a barrel due to round count then that bolt is completely disassembled and placed in my spare parts bin so I know it is a "used" part and never mixed with the "complete new bolts" - I never throw old parts away, as they are always saved and yes in a SHTF situation they would and could be utilized. In such a situation they'd be like gold or money in the bank.

Too many folks buy firearms, but never perceive of the need for spare parts - for what good is the best rifle if ya break a firing pin, extractor, ejector or bolt ya ain't got?

Swapping bolts around leads to broken bolts, which is not an issue today, but one day it might be.....

I actually started to build a complete upper in 300 Blackout to go on my 5.56 lower, but while I was waiting on parts for the upper I ended up building a complete lower. So both of mine are complete rifles with their own BCG.

 

[Younggun]

I've yet to see any issues from BCG sharing either in my own experience or reading the experiences of others.

Do I throw my BCGs on a pile and randomly grab them for random rifles? No.

Do I think it will make one bit of noticeable difference in a range or hunting rifle to share a BCG with another rifle for a while? Nope. Just haven't seen any evidence to support it aside from a bunch of boogeyman posts on the internet.