Originally Posted by
Gubermonkey
Well, got mine, and there are several issues.
1; steel mags don't work. The milling in the upper reciever is more rounded and doesn't allow the "square" leading edge of the mag to sit high enough to become seated. Pmags seem to work. Doesn't help much since this was a Grendel build.
2: safety is ridiculously tight almost immovable. Though I'd sand down my selector switch, no luck. It appears that the holes drilled for the selector switch in the reciever and the trigger block sleeve don't line up perfectly. Stupid, annoying, I could fix that but that's definately another manufacturing defect.
3: most importantly, like other have experienced, very tight tolerances with regards to pins. I decided to sand down my roll pin for the bolt catch. It was working until the last 1/4 going in, I hear a crack, and there it is, a nice crack going lengthwise in one of the bolt catch "ears". It didn't crack where they attach to the side of the reciever, the roll pin itself split the aluminum.
Don't say I was being too tough with it, not my first ar(ish) rifle I've built. I sanded that pin down a LOT. There's no way that hole would be of any acceptable specification.
Only plus side is that the rifle looks sexy as hell, and macdef actually asked me to send the reciever back to them. Lets see what comes of this.