According to my Green Mountain Chart... they have drop in barrels for the Cabela's Hawkins, Investarms, Lyman Trade Rifle, Lyman Deerstalker, Lyman Deerstalker carbine, the T/C Hawkins, Renegade. Renegade Hunter, and T/C Big Bore.

With these drop in barrels they range in caliber from .32 - .50 in fast and slow twist barrels. In order to get the bigger calibers, you have to go to a Thompson Center .54 caliber rifle and then you can get a drop in all the way up to a .62 caliber.

Good luck with your selection.