Andy is pretty paranoid about 21 rib separation, warns that the ribs must be completely removed along with the forend lug because "there may be serious rust underneath and good possibility of perforated barrels". For this reason, he is a little pricey for his rib repairs, but I'm sure he does very good and thorough work. Yes, they do pop, usually in conjunction with a loose forend lug. One could be the cause of the other. In better than a dozen 21s that have been in and out of my house, one has a popped rib, has not been fixed, but I will get to it some day. The gun probably has tens of thousands of rounds through it, owes me nothing. I will probably send it to Andy because he claims he will completely dismantle the barrels from the ribs and examine them. The small soldered area on the forend lug and the fact that they are almost all beavertails is the reason for the problem in my opinion. I don't know whether Tony has more support on his forend lugs than the older guns.
