With this many guys having the same problem I am willing to bet that the chambering reamer they are using is SAAMI min dimensions or less. Check your fired brass to see if there are small annular rings around the bodies of the brass which will indicate that there are annular rings in the chambers caused by a bad reamer or burr hanging up during reaming. They will act to grab the brass. I have seen it happen on bad semi=auto pistol barrels.

El Lobo