The thicker portion of the barrel of a gun, forward of the breech, and leading to the chase. There may be first and second reinforce, the first being that starting at the breech. Earlier models often had a molding, or at least a sharp discontinuity, between the reinforce and chase, as with the M1841 six-pounder gun, but this was usually smoother, almost invisible, in the more common guns of the Civil War period.