The monoblocks are milled from solid stock. However I have sleeved cut off tubes on 2 maybe 3 guns that had unusable barrels. I won't take a perfectly good set of shotgun barrels and cut them. My own personal choice. I must say that I'm really not a fan of using the cut off method unless the shotgun barrels were originally chopper lumps or they were originally a true monoblock.

Now to be fair the biggest caliber I've made is a 50/70 but the most powerful has been a 9.3x74r that was my last and currently my favorite.

The monoblocks work great but I've been milling an action now for a couple of months that is a snap action (underlever) with the Purdy style locking lugs and all of the mechanical stuff is mounted to the trigger plate. The back of the lacking bar will actually cock the internal hammers. This one uses some flat springs but I'm trying to figure out to get where i want using coil springs on a plunger. That way even if they break they have a high likelyhood of still working.

BB