dleong's experience with the Rock River part kit reminds me of my own. Instead of a defective trigger though, they sent me a cracked mag release.
They have these parts made by subcontractors, and I guess they figure it's easier to let the customer do the final inspection, than pay someone at their plant to do inspections.
That pisses me off royally
Their recievers and barrels are good quality pieces, but I'll not spend any more money on internals with them. Oh yeah, the bolt head I got from them had edges so sharp you could darn near cut your finger on them. That's an open invitation to 1)shaving brass shreds off the back of the cases, eventually causing malfunctions (and how mwny posts have we seen on those events?), and 2)paving the way for the bolt head cracking at the hole (and how many post have we seen on aftermarket bolt doing that?)
Put a GI surp, Colt made, bolt in mine, traded off the RR piece towards a Colt upper, and haven't looked back[:D]