I see AR-15 uppers and lowers for sale quite a bit but have never purchased anything other than a complete rifle. How do you know if an upper/lower will match? Are all or most AR-15 components uniform enough to swap between different brands of rifles. Not sure if I'm asking the right questions here so any help would be appreciated. Thanks.
Posts: 1346 | Location: NE | Registered: 03 March 2002
About the only hitch btwn AR uppers and lowers is that there for a while, Colt used a different pin size on some of their receivers, so there are 'large' and 'small' pin receivers. I think they stopped that nonsense a while back, but even if they didn't, pretty much everybody else uses the regular (large) receiver. Btwn the larger manufacturers like Bushmaster, DPMS, & RRA I think things should be uniform enough to not have to worry. Some of the odds-n-ends from smaller manufacturers might need checking, but otherwise you should be good to go.
Monte
Posts: 341 | Location: Wenatchee, WA | Registered: 27 February 2002
The only AR-15s I've had experience with are Colt and Bushmaster. The Rock River Arms guns are supposed to be very good rifles but I'm clueless as to the rest. My cousin is chomping for a DPMS heavy barrel varminter so any feedback on those or any others would also be appreciated. Thanks.
Posts: 1346 | Location: NE | Registered: 03 March 2002
Most uppers and lowers are compatable. I have built several rifles from parts and am very happy with the DPMS barrels, although, Olympic Ultra Match barrels are also very good. I've had two bull barrels in .223 from DPMS that are tack drivers. There seems to be more parts variablility in the trigger group in my experience, so you should not only make sure they have the proper pin size, but also take a good look at the sear angles on the hammer, trigger, and disconnector. It will make a big difference in the trigger pull if you plan to use stock parts.
Posts: 238 | Location: Memphis on the mighty Mississippi | Registered: 19 December 2002
Nebraska, I have put several together for varmit hunting and shooting paper and I found that my current one is the best so far. It is built on a Diamond lower with a Olympic 20" SUM flat top bull barrel. Setting up top is a Mk 4 10X target dot in Mk 4 rings.
Posts: 1605 | Location: Wa. State | Registered: 19 November 2001
