I started buying RRA lower parts, intending to build an all-RRA rifle 'cause I like uniformity.  Either RRA changed or I didn't do enough research, though, because yesterday I found out they don't offer the configuration I want (chrome-lined 20-in barrel in standard A2 style).  So now I'm thinking about a Bushmaster upper.  My question is:  are there any potential problems with mixing parts from these two manufacturers?  Are AR parts truly interchangeable?

Actually, this might work better as I can get the government-profile barrel from Bushmaster - I want to build an M16A2 clone.  What are the pros & cons of HBAR vs gov't profile?

Tim

they are interchangable.



though rra lowers have a higher rear shelf and the upper/lower fitment might be a little tight at first but nothing to harm the mechanics of the rifle itself.