Anyone ever seen this?  I just built a RRA M4gery with RRA barrel and upper.  When I test fired the creation, the windage adjustments were way off to the right.  Closer inspection revealed the FSB canted (just barely).  Took the beast apart and discovered the slot for the barrel pin was not centerd with regards to the upper receiver.

It's been discussed here many times.  Lightly file the barrel indexing pin slot.  Align barrel / FSB, and stake open side of gap with a punch.  Put her back together and your good to go.

if you bought it from a dealer i would ask for a replacement of even try to talk to rra and see if they will do right.

i usually here this about bushmaster and some of the others but i have to say this is the first time i heard about a rra.

Quoted: if you bought it from a dealer i would ask for a replacement of even try to talk to rra and see if they will do right. i usually here this about bushmaster and some of the others but i have to say this is the first time i heard about a rra.

The Bushie problems seem to have been a question of the barrel nut being over tightened, driving the steel locator pin into the left side of the slot in the aluminum upper, causing the piece to shoot to the right.

Frankly, at the rate that ARs are being cranked out these days, it doesn't surpise me that stuff like this occurs. Cerainly, if you bought the upper/barrel as an assembled unit, I'd send it back to Rock River.  If it was a total homebuilt, the fix suggested should work.

Just remember, it doesn't take but a couple of thousanths shift at the base of the barrel to change the point of impact inches at the target, so if you do it yourself, work slowly and carefully

This is covered in the Q&A here:

www.ar15.com/forums/topic.html?b=3&f=4&t=226782