Rabbit;
Off hand I can think of the following methods of joining bbls at the breech;
Conventional, Dovetail, Through lump, Shoe lump, Chopper lump, Dovetailed Chopper lump, Monoblock & Demi-block (as far as I know another name for chopper lump or DT chopper lump).
As mono-block is one of the factory methods of joining bbls in which the block with lumps & rib extension, if used, is all milled from one (mono, means 1) piece of steel is why I am so adamant that cuting off a section of bbls quite likely assembled from four pieces, "Does not a Mono-Block make". The term "Sleeving", admiting many consider this to not be actually descriptive of the process involved, has been used a number of years & marked by the British, is not named in any of the existing methods of breech assembly. I see no reason to change terminology.
