Since "White Lightning" liners were mentioned I must warn you folks who have a 1/4-28 thread or a M6 thread in your barrel for the vent liner, YOU CANNOT REPLACE THE EXISTING LINER WITH A WHITE LIGHTNING LINER OF THE SAME SIZE. The White Lightning liners ALL use a 32 thread pitch which cannot be screwed into your barrel. The existing hole cannot be re-threaded to a 32 pitch thread either. Any attempt to re-thread the hole to the 1/4-32 thread will result in a hole without enough metal in it to withstand the pressures from firing the gun. The only way to switch to a White Lightning liner is to go to the next larger thread size so, if your gun has a 1/4" or M6 threaded hole you must use a 5/16" size White Lightning liner. On guns with large octagon barrels that might not be a problem but for many guns, the width of the flat on the side of the octagon barrel will be less than 5/16" so, the 5/16" liner will be sticking out of the neighboring flats making the whole thing look like it was done by a shade tree mechanic who doesn't know beans about muzzleloading guns.