Initially I started builing a Ar. I got my lower together in about 45 minutes. Other projects and guns kept taking priority. I sold my lower and gave up after talking with the BATFE. I hold an 01 FFL an had the brilliant idea of putting some rifles together. They explained that this would be Manufacturing and would require yet another license.

Well, long story short, I have just order a new complete RRA lower. I amwantin at least 2 uppers for it. I plain ol vannila A2 for shooting burglars and I want to put together a precision varmit upper for winter fur collecting.

My basic question is. I really don't want to be locked into on company for parts. Would there be any trouble with a DPMS upper on a RRA lower, for instance?

You can mix and match most parts.  Some Colt parts being the exception.  DPMS and RRA will work fine together.

Thanks.

No problems....my first build was a DPMS complete upper on a RRA lower build.

Mike