I have 2 carbine barrels in flintlock. One is a 21" TC PA Hunter barrel in 1/66 twist; this barrel shoots ball well and ball-ets pretty well to 50-60 yards which is about the limit I will shoot it at deer. It shoots best with 60 grains of 2f but will handle up to 80 grains and keep a good group; not alot of power but can keep it well under 3" groups at 50 yards. I don't shoot it much though as I will take the longer barrel for deer hunting most of the time if I am shooting balls or ball-ets. I do like it alot but I don't use it much; It's great for deer drives and tree stands in heavy cover. Quick to point and the ball-et hits with a good thump.

My second carbine barrel is for a RMC flinter rifle; this barrel is a Green Mountain 24" long .50 caliber and 1/28 twist. It is by far my favorite hunting flinter and groups under 3" @ 100 yards is normal course of action for this gun. It shoots Great Plains conicals and saboted pistol bullets. It even has shot very good groups with a round ball with 80 grains of powder. I have the same barrel in 28" long for the same rifle but the 24" is the barrel it wears most of the time. I think if I was going to build a half stock rifle I would make it 26" and it would be plenty handy and still have a little barrel length for more efficient burn, larger charges and a bit longer sight plane. I think the TC Renegade's are 26".

I think everyone should have a carbine switch barrel for their sidelocks with the hook breech tang. I do think the 21" barrels are a bit too short though.