It's a .54 caliber 1:66 twist. My only regret is I didn't go with a .58. The barrel was a NOS Douglas made for a CVA Mountain Rifle. He cut off the drum breech and installed a slanted snail breech. with a doll head tang. It measures 31 inches which is a little short for a Hawken. I was going to go with a 36 inch Green Mountain but he made me a deal on the Douglas I couldn't pass up. I figured I could always swap it out later but it shoots so good I decided to leave it. The trigger guard, butt plate, toe plate, ramrod thimbles, barrel keys and escutcheons are all hand made. The barrel keys are pinned. The lock is a Chambers. The triggers are from an original English rifle and they are nice. The nose cap is a Ted Cash. The rear sight is a full buckhorn. The front sight is a Hawken blade. The stock is figured maple and has the correct contours of an original Hawken. It even has a slight cast off which fits me perfectly. It's not a perfect copy of an original but it's close enough for me.