You can always turn the barrel a little to INCREASE the difference, thus allowing for a thicker sleeve
This could possibly also be accomplished by reaming the block.
Again, this is to increase difference so you can use a thicker sleeve. The barrel has more steel to "lose", but requires a lathe.
This could possibly also be accomplished by reaming the block.
Again, this is to increase difference so you can use a thicker sleeve. The barrel has more steel to "lose", but requires a lathe.