I've got a blank, half octagon, half round, 28 inches long. has 1 1/4" long shank, 1" dia, then 1.065 octagon, 11 inches long. Round tapers from 1.040 to .990 at muzle.
Rifling is 9 twist, was a Montana Rifleman Blank, custom contoured. Twist is a bit fast for lighter bullets, but would work okay, and would allow shooting heavy bullets. Finish is excellent, polished and bead blasted lightly, very little work to rust blue these. $235 shipped for this barrel.
Also have a 16 twist centerfire, 3 groove Benchmark, 33 inches long, shank is 1.150" round, 3 1/2 inches long, transitions to octagon then tapers from 1.090 to .955. Octagon is 29 inches long, with 1" muzzle waste after that. Benchmark has been winning a fair amount of benchrest with their barrels. I'd like to get $300 shipped for this barrel. It would make a dandy .22 hornet for 40 and 45 gr bullets.
dave