I never bought a drop in barrel, nor would I. I fit breech plugs, sights, underribs and tennons myself. Aint rocket science. GM barrels have better rifling than TC barrels. If Green mountain uses a helicoil to breech their drop ins, that is a major accident waiting to happen. They still make better rifling. I've graduated beyond GM barrels in my shooting. Although I still have one or two on the rack in my shop. If I were to build a gun for a relative to hunt with, I'd probably use a GM. For the most part TC makes a quality gun, there is room for improvement, the barrels and their frizzens are their sore spots.