Anyone put a collapisble stock on their 20" AR?

[Parkshow30]

Just like the title says, I have a 20" Bushmaster I want to put a collapisble stock on because in the smallest position, it will fit in my BOB. Anyone have one on theirs? Does it make the gun too front heavy? Any replies are appreciated.

[01coltcolt]

Just like the title says, I have a 20" Bushmaster I want to put a collapisble stock on because in the smallest position, it will fit in my BOB. Anyone have one on theirs? Does it make the gun too front heavy? Any replies are appreciated.

I carried that configuration the last time I was in Afganistan. with a A2 upper and a EOtech mounted on top of the Surefire RIS. It shortened it up and was easier to carry with a wolf hook on my tac vest.

[Ljunatic]

If it is a Govt. profile without a bunch of gear on the rail, then it works out OK

I have an 18" rifle with a VFG, bipod and a scope that is manageable with a Magpul CTR

http://i197.photobucket.com/albums/aa61/LJUnaTIC/Rangeday003.jpg?t=1214536230

[remat]

I have temporarily swapped my 20" BM Govt profile barrel upper onto a collapsing stock lower (easier to carry only 1 lower shooting). Amazingly it doesn't handle too badly. I am kind of a traditionalist though, I think it looks kind of strange.

[Onmilo]

These variations first bacame popular with African mercenaries in the 1970s.
They liked the full size M16A1 rifles for the punch the ammo had and they liked the CAR15 stocks because they made the rifles easier to transport in a vehicle.
This is an A1E1 variation I built a while back;
http://www.fototime.com/8060F841B186588/standard.jpg

The Canadians offer the C7A2 full size rifle as standard with a telescoping stock now.
A telescoping stock weights nearly the same as a standard stock assembly so balance is not adversely affected.
In many cases it actually improves because the length of pull can be tailored to the individual shooter.

[planner]

My first AR, a Colt Sporter purchased new in 1973 came with a collapsable stock. I later had a custom CAR15 upper built (because Colt did not yet offer a "carbine"). But I decided that I preferred the full-size AR and got rid os the stock and upper. Even though I now have 2 full-size & 1 M-4rgery, I still prefer the full-size, non-assist, 20" Ar platform

[python357]

I've done it, but it makes the gun feel a bit nose-heavy.

[MrMurphy]

The Army is slowly in the process of switching all A2s to collapsing stocks once they choose the model and maker, a request for info came out a while back about it. Everyone likes the M4 collapsing stock, so it makes sense to give people the ability to fit the rifle to them even with a full length rifle.

[bno762]

I have been wantn to do this with my bushy 20 inch hbar. When u swap the buttstock do I keep my buffer tube or swap for a carbine lenght? If swapping can this affect reliability? If this sounds stupid sorry Im still pretty new to the ar.

[Parkshow30]

I have been wantn to do this with my bushy 20 inch hbar. When u swap the buttstock do I keep my buffer tube or swap for a carbine lenght? If swapping can this affect reliability? If this sounds stupid sorry Im still pretty new to the ar.

My question as well, I have seen them for sale with and without the buffer tube, not sure if the one in there will work or if I need to pay a little extra for the new one.

[Texas357]

Why do barrels always seem to come in 16" or 20" flavors? I don't remember ever seeing an 18" AR barrel.

[orlando_5]

I have been wantn to do this with my bushy 20 inch hbar. When u swap the buttstock do I keep my buffer tube or swap for a carbine lenght? If swapping can this affect reliability? If this sounds stupid sorry Im still pretty new to the ar.

In your example I assume you have A2 buttstock and buffer tube. The simplest way is buy the complete collapsible carbine stock with buffer tube and spring. This will save you a lot of pain because buffer tubes comes in military and commercial spec. Military buffer tube does not work with commercial stock. Military stock does not work with commercial buffer tube. In other words, both stock and buffer tube has to be same.

An A2 buffer tube will not work with collapsible carbine stock because the buffer tube doesn't have notches to capture the stock. You need a carbine buffer tube to work with a carbine stock.

It would not affect reliability.


Why do barrels always seem to come in 16" or 20" flavors? I don't remember ever seeing an 18" AR barrel.

They comes in 18". These AR15 is called SPR. I am thinking about building one in the future.

[Onmilo]

Commercial vendors like to call 18" barrel versions "Mid-Length" because of the location of the gas port and gas block/front sight housing which is, well, midway between the 20" barrel gas port location and the 14.5"/16" barrel gas port location.

[bno762]

In your example I assume you have A2 buttstock and buffer tube. The simplest way is buy the complete collapsible carbine stock with buffer tube and spring. This will save you a lot of pain because buffer tubes comes in military and commercial spec. Military buffer tube does not work with commercial stock. Military stock does not work with commercial buffer tube. In other words, both stock and buffer tube has to be same.

An A2 buffer tube will not work with collapsible carbine stock because the buffer tube doesn't have notches to capture the stock. You need a carbine buffer tube to work with a carbine stock.

It would not affect reliability.




They comes in 18". These AR15 is called SPR. I am thinking about building one in the future.


Thanks for that. I'll prolly grab one this weekend then.

Parkshow30- thanks for the thread. I'd been wondering about it and wantd to ask but then again I didnt want someone being all "hey look at the newbie ar guy blah blah..". But then again yall wouldnt do that.....would you?:supergrin::whistling:

[crazymoose]

Commercial vendors like to call 18" barrel versions "Mid-Length" because of the location of the gas port and gas block/front sight housing which is, well, midway between the 20" barrel gas port location and the 14.5"/16" barrel gas port location.


Mid-length refers to the location of the gas port, not the barrel length. Mid-length was originally developed for 16" barrels to alleviate the extra abuse the rifle receives by having a carbine-length gas system with a 16" barrel (with that setup, there's too much barrel in front of the gas port). The mid-length gas system on a 16" barrel leaves as much room between the gas block and muzzle as there is on a 14.5" w/carbine gas system or a 20" w/ rifle gas setup.

As for gas systems on 18" barrels, there is some controversy. Most people like a mid-length gas system on an 18" barrel because there is more pressure and therefore, in theory, more reliability if the rifle gets gunked up. Some people argue that a rifle-length gas system is proper for an 18" barrel, as there will be less gas pressure so less stress will be put on the bolt and other internals.

[Ljunatic]

Mid-length refers to the location of the gas port, not the barrel length. Mid-length was originally developed for 16" barrels to alleviate the extra abuse the rifle receives by having a carbine-length gas system with a 16" barrel (with that setup, there's too much barrel in front of the gas port). The mid-length gas system on a 16" barrel leaves as much room between the gas block and muzzle as there is on a 14.5" w/carbine gas system or a 20" w/ rifle gas setup.

As for gas systems on 18" barrels, there is some controversy. Most people like a mid-length gas system on an 18" barrel because there is more pressure and therefore, in theory, more reliability if the rifle gets gunked up. Some people argue that a rifle-length gas system is proper for an 18" barrel, as there will be less gas pressure so less stress will be put on the bolt and other internals.


This won't end the argument of Middy VS Rifle, but my RRA with rifle length gas runs every type of ammo i have tried without failure , including Wolf

[Onmilo]

OK since we need to get super technical, yes you can use a mid length gas system on a 16" barrel.
What does it get you?
Slightly longer handguards and the option of mounting a bayonet on a 16" barrelled rifle, something one cannot do with a 16" barrel and a standard carbine gas port location.
Since we are getting all technical here how about some trivia?

What was the name of the engineer who brought the mid length gas system to fruition and why did he do this?

[crazymoose]

OK since we need to get super technical, yes you can use a mid length gas system on a 16" barrel.
What does it get you?
Slightly longer handguards and the option of mounting a bayonet on a 16" barrelled rifle, something one cannot do with a 16" barrel and a standard carbine gas port location.
Since we are getting all technical here how about some trivia?

What was the name of the engineer who brought the mid length gas system to fruition and why did he do this?


It's not just that you can use a mid-length on a 16" barrel, the mid-length was actually designed for those barrels. The carbine gas system has never been very kind to the internals of an AR, and the problem is even worse when you go from an 11.5" or 14.5" barrel to a 16" barrel. The point of the mid-length is to reduce gas pressure (from about 30K to about 20K PSI) and increase dwell time, thereby making the extraction process less violent and prone to jamming or case head separation. Armalite was the first to do this, though I'm not sure who was involved in the process. Topp, maybe?

[remat]

OK since we need to get super technical, yes you can use a mid length gas system on a 16" barrel.
What does it get you?
Slightly longer handguards and the option of mounting a bayonet on a 16" barrelled rifle, something one cannot do with a 16" barrel and a standard carbine gas port location.
Since we are getting all technical here how about some trivia?

What was the name of the engineer who brought the mid length gas system to fruition and why did he do this?

I just read this on 68forums in a discussion about Armalite:
A quote from Gary Paul Johnston in SOF Magazine...

"You see, the original AR-15 rifle was carefully designed by L. James Sullivan and Robert Fremont, of the original Armalite Corporation, to place the gas block at a location well beyond the apex of the pressure curve of the 5.56mm (then the .222 Rem. Special) cartridge around which the rifle was designed. The development of the 292mm barrel XM177E2 (CAR-15) during the Vietnam War went far beyond what was expected of the design, putting the gas port at or near the maximum pressure curve in the barrel. The same location of the gas port in the 14.5-inchM4 barrel hasn’t made the problem any better and the velocity of the bolt group remains extremely high. The best answer with this short barrel is a gas port that is a compromise between the two—the mid-length. "

[Onmilo]

Ding, ding, ding, we have a winner!
Mark Westrom of the current Armalite went ahead and perfected the concept from those original designs and brought the whole mid-length concept to the commercial market.