RRA upper with Bushmaster Lower?

[zach13168]

I'm going to buy an upper for my Bushmaster, and I came across a RRA upper that looks like a good buy. My question is can you put a RRA upper on a Bushmaster lower with maximum reliability? Also can other RRA and Bushmaster parts (carrier group, firing pin, cam) be switched around?

Zach

 

[yesterdaysyouth]

as long as all the parts are mil-spec you shouldn't have any problems...

so yes and yes...

 

[Rexrider]

The RRA upper should bolt right on. You can use the bolt/bolt carrier from the Bushmaster if you wish.

There is no way to determine "maximum reliability" until you take it out and shoot it.

Side note: If intend to swap uppers back and forth, get another bolt/bolt carrier group so you have one for each upper. You may get accelerated wear with the bolt and/or carrier if you keep swapping back and forth. If you are only swapping it once then you should be okay.

I prefer to keep a bolt carrier group with it's own upper but that is personal prefrence. It is not un-safe to swap them.

 

[Zach S]

My AR is comprised of an assembled BM lower, a RRA 16" A4 upper and 6 postion stock. Runs great. Colt 20 round mags dont drop free from my lower, otherwise I've had no issues. RRA amd BM both use standard pins, so you shouldn't have any problems, but I will second Rex's suggestion for having a bolt carrier for each upper.

For some odd reason I feel like I'm talking to myself...

 

[Master Blaster]

I have done this twice, and both rifles a varmint upper and Bushie lower with a RRA 2 staget trigger in the lower, and an M4 copy run great. The fit of the upper to the lower, and the finish on the RRA upper is better than on my all bushmaster factory assembled rifle. Both my RRA uppers came with a bolt and bolt carrier from RRA.

 

[BryanP]

My AR is built around a Century stripped receiver. The people who made those receivers are the same people who make RRA's. The rest of the lower is DPMS parts. The upper is a Bushmaster. The bolt, carrier & charging handle are RRA. I've never had a bit of trouble with it.

 

[unreal45]

Yes this setup will be reliable.
IMHO RRA's finish is a little higher quality than Bushmasters.
Check out www.ar15.com for more than you would ever want to know about ARs.

 

[MAUSER88]

No problem at all. I have RRA Varmint on my Bushy lower.