NEW PRODUCTION THOMPSON CENTER BARRELS MADE IN NEW HAMPSHIRE, THESE BARRELS HAVE THE NEW BLACK NITRIDE COATED SPEED BREECH AND 1 IN 24 RIFLING. PLATFORM: THOMPSON CENTER Encore PROHUNTER. CALIBER: 209 X 45CAL MUZZLELOADER BARREL W BLACK NITRIDE SPEED BREECH. RATE OF TWIST: 1 IN 24. 875 HEAVY CONTOUR ANY MUZZLELOADER FOREND WILL WORK FINE. FOREND SCREW SIZE/SPACING: 1/4-28 MZLDR ADAPTORS / 5 Centers. SCOPE BASE: DRILLED AND TAPPED FOR ANY STANDARD TC 4 HOLE BASE. SIGHTS-DRILLED AND TAPPED PREP ONLY.