I received the second barrel tonight. Upon installing, it hung up just like the first one. I decided to wiggle it a bit with some light downward pressure. This caused it to slide on in. I tried the same thing with the first barrel, and it too seated fine. In contrast, my original 18-inch barrel drops right in, with no extra effort required. Since that is what I am used to, I expected the longer barrels to behave the same way.
Putting the gun back together with one of the long barrels, the action seems to be functioning fine. I am going to a shoot on Saturday, and will put a few rounds through it to confirm. I will follow up on Saturday evening with a function report.
Thanks,
James