The T/C White Mountain Carbine is an excellent ML. The .50 caliber models came in 1 in 20" twist rates, and 1 in 38" twist rates. The early production ones had the 1 in 20" twist. The .45, and .54 caliber models all had a 1 in 48" twist rate. I own several .54's and they are very good patched round ball shooters. 80 to 90 grains of Goex FFG, with an .018" pillow ticking patch, Hoppes #9 Plus Black Powder Solvent And Patch Lube, with a .530" round ball work well. I have owned, and shot these ML's for years, and have never experienced a crack in the stock. You will like it !