Sleeving involves pulling the ribs, cutting off the barrels about 3-3 1/4” from the breach, boring the remaining holes in the “monoblock/breachblock to the same dia as the rim cut, stubbing new barrels into said holes, and relaying ribs. Of course that’s a simplified version.
Judging by your nomenclature I think you might be talking about lining, which is a completely different job although some people confuse the two as similar.
Lining involves boring the barrels their complete length, and installing a full length liner into the original barrels.
I don’t believe anyone in the world is still doing shotgun lining unless Teague is still involved in it?
I only sleeve.
