My new 9mm RRA upper won't fit my RRA lower.  WTF?  The rear lug needs to be filed down.

Post this in the RRA industry forum, you will get a response DIRECTLY from RRA who can actually do something to correct the problem.

RRA lowers are made tight at the rear lug area ! Usually all you need to do is apply some CLP on the lug and hand force it together . After a couple of times it will fit like a glove .

honestly, the first couple times I disassmbled my RRA, I had to take a soft mallet to the back of the upper to seat it to the lower.  It was super tight.  Now I can to it by hand, but it's still really tight.

Quoted: honestly, the first couple times I disassmbled my RRA, I had to take a soft mallet to the back of the upper to seat it to the lower.  It was super tight.  Now I can to it by hand, but it's still really tight.

Beat me to it.  Try a rubber mallet.  I've had to tap rear push pins in before cuz they were so tight.

I bet everyone wishes they had THIS problem.  I bought my first RRA product in 01' and it was pretty tight.  They seem to have gotten better.  I just picked up another one and it was super-tight- couldn't ease it together without bumping it pretty good.  

I handled about six new rifles last week at one dealer by various manufacturers (who shall remain annonymous but their names start with A or B) and ALL were fairly loose.  You notice the play immediately when you pick them up.  I would hate to start out with one that's noticeabley loose as it will loosen up more with use.

Anyway, sp1shooter did post on the RRA forum and got his answer from the mod.  This problem usually isn't a problem.

I'm going to wait until I get a new 9mm marked lower to fit it to.  This is the third RRA I have built and none were this tight.  I guess I won't complain!  Thanks for the replies.