Pugwash , I don't know who dose the sleeving you refer to but if it is done correctly the tubes should be a drive in fit . NO gaps . I recently saw a sleeved gun that had been tinned ,the tubes were coming out ,when cleaned off for re tinning there was a .006" difference between the tube and the back end and had relied solely on the tin to hold them together . Had to have new correctly fitted tubes . Some mono block guns ,Beretta for example tin the tube into the mono block and I have known these to come loose as they are not a tight enough fit in my opinion ,but having said that it is a very rare occurrence give the number made.Others like Miroku and other Italian guns appear to be silver soldered /brazed as are the ribs . As with every thing else there are good jobs and bad jobs .
