37in – 1:66 Twist
Colerain Barrels are drilled from solid bar stock, using a radius 6 lands and grooves rifling of .012 deep for 40 caliber and .016 on all others. This produces round bottom grooves which promotes less fouling and easier loading and cleaning. All barrels have crowned muzzles for loading ease and come with installed breech plug.
The Edward Marshall is a 37″ swamped barrel which can be used on an early transitional rifle. .62 Caliber, D weight, 1:66 twist.
