Our 31" swamped barrel is modeled after barrels used on German, Austrian and Swiss Jaeger (hunting) rifles, the type of rifle first made by the European gunmakers who emigrated to America.
Colerain Jaeger barrel has a 1.125" breech, .890" waist, 1.020" muzzle. The breech is threaded 5/8-18 to accept a breech plug. No breech plug is fitted.
Colerain barrels are cut rifled with fancy radius groove rifling, in these correct twist rates for round balls:
1 turn in 48 inch twist, in calibers .36 or .40
1 turn in 56 inch twist, in calibers .45, .50 or .54
1 turn in 66 inch twist, in calibers .58 or .62
Colerain rifle barrels are the favorite choice of today's best muzzle loading gun makers, because knowledgeable shooters demand Colerain's accuracy, inside and outside. Founded by two entrepreneurs, Scott Keller and Scott Kelly were tutored by Bob Paris, the famous rifle barrel maker who was first to perfect the technique for production of correct swamped barrels.
Colerain rifle barrels are drilled from solid steel, cut rifled .012" to .016" deep depending on caliber, with six "round bottom" grooves. Called "radius groove rifling", Colerain eliminates the sharp inside corner that accumulates fouling. Radius groove rifling cutters are a bit more expensive to make, but Colerain's customers agree that the accuracy, easy loading, and easy cleaning are worth the cost.