CDNN had a real good deal on Bushmaster AR stripped upper so I picked one up. Finished putting the forward assist and dust cover on then slid a BCG in to see how it worked, BCG was very tight fitting and am wondering is this normal for a new upper?
CDNN had a real good deal on Bushmaster AR stripped upper so I picked one up. Finished putting the forward assist and dust cover on then slid a BCG in to see how it worked, BCG was very tight fitting and am wondering is this normal for a new upper?
What brand is the BCG?
When you put the BCG in it should slide freely (make sure dust cover is open) so tip the upper up and down if the BCG stays in place than I would say something is out of spec. If I were you I would bring it to the range and see if it functions. If you shoot 100 rounds with no failures I wouldn't be very worried, just keep an eye on excessive wear on the bolt when you are cleaning it.
The BCG I installed was a Bushmaster from a 1990's rifle with real low round that I took out too replace with a M16 BCG. To my thinking I'm dealing with a thick phosphate coating that will wear in with a few hundred rounds? Plan on building a .358 Legend as soon as KAK builds some more barrels so we might be in for a little wait as far as seeing if the upper wears in.
Just got up from the keyboard and went to the shop and pulled the BCG out of the new top end and replaced the Bushmaster with a Colt. Fit was a pinch better but could see that the tight spot was at the bottom and top of the ejection port. I might do a light polish on the bottom rails of the carrier and that might do the trick.