Quote Originally Posted by old tanker View Post
as Brit Plumber has surmised
Really...just him? Check post #2.

Quote Originally Posted by old tanker View Post
God knows why, a shim added by somebody.
Go back and re-read from the start and you'll see why it was added. Those are the ones you can buy in sets from Brownells and others...for tightening a loose Mod 10 S&W for instance...