Using milling machines it is easy to machine a monobloc, the lump being cut via crop milling and later chased out by hand to form the bites.

Whoever first patented the monobloc, it is the Continental makers who employed it from the start and later refined it. The British resorted to sleeving in the 1950s and although sleeving looks like a monobloc it is not. The breech part that remains in sleeving is a composite part, depending on which barrrel method was used, not a unitary piece of steel.