So, I decide to add a flip-up rear sight to my flattop, as a backup to my OKO.  I go to the gun store, buy the sight, try it on and  %#^%^& it doesn't #$E#@@& fit!!!  Every other damn AR I tried it on it fight fine - wtf?  Is this a Rock River Arms problem???  A LEGP problem?

The only 2 I've found that fit the LEGP so far were from Knights Armaments & those cost over 200 bucks!  I'm thinking of ordering Bushmaster's but I don't want to get it & find out it doesn't fit, then have to send it back...

The thing is the OKO fits fine, I guess it "hitches out" wide enough to fit onto the rail...  Any ideas, info of use?

I believe RRA had a run of out of spec rails on the A3 receiver.  Not sure if the LEGP was part of that run.  In any case, not much you can do but machine it or replace it.

Ass. Thanks for the responses guys.  This is complete & total bullshit, but I blame myself in part for not checking this when I got it.  A heads up from RRA or Castle woulda been nice...  Maybe the fact that the OKO fit perfectly threw me off.  Anyway, not much I can do about it now.  

I wonder how far out the Bushmaster flip-up cantilevers out? I'd rather buy it for $75, than the Knights for >$200.  Guess I'll do some measuring soon...