I have several barrels that have shot extremely well from day 1, a .45 and a .50 by Bill Large, a .58 by Green River Rifle Works, and a .73 by Riley Smith of Long Hammock Barrels.

Then, I have a .45 w/1-22" twist from Navy Arms that has never shot worth two hoots, and never will.

A good custom barrel by one of the well-known makers comes from the shop "broke in". No telling what has to be done to get a typical production-line ML barrel shooting well......