Here's the "Silver Bullet" fix. Drink a can of Coor's beer, enjoy, cut the can to get the rectangular piece the size you need. Place it in the hook and try the barrel on the action. If it's too tight, you can shorten the piece you cut by about .060 and try it again. The pin will shape it to the hook, so keep cutting the .060 off and when the action fits right, glue it in place using either "Shoo Goo" or "Mechanics Goop", both available at Wally-World. This stuff will glue anything to anything and hold till you cut it out with a knife. If you ever wear this shim out, which I've been unable to do, repeat the process, and as always, enjoy...[brand optional].
binko