It depends of which era Replicas we are talking about. Those Percussion replicas made before the year 2000, usually had cylinder chambers that were "Funneled" with metal steps in them. Toda6ys replicas are strait walled and generally there is no need to take any more metal out, with the advent of Hotter more powerful powders like Triple Seven, Swiss, Goex Old Eyensford, Black Mag 3 ,Black MZ, Pyrodex, Super Powder, etc the newer strait walled cylinder will suffice as in hunting purposes. The older cylinders especially in Colts I recommend those who wish to hunt with them to take out the extra metal. There is no structural problem or weakness in doing so, provided it is correctly done. My friend Master Black Powder Gunsmith Mr. Dykes Reber of the Muzzleloader Shop in N Little Rock Ark. He offers this and all major repairs and modifications on Percussion Revolvers. You can contact his shop at 501) 758-2222.