[Kensal Rise]

British gunsmith, Kirk Merrington, has made me aware of an increasing trend in his barrel repair work: "Pimple Bulges."

Apparently, these amount to a bunch of small bulges in the barrel, shaped like small skin pimples. Those who acquire them in their double guns are baffled as to the cause. And they almost always appear in the left barrel, along the bottom of the tube.

If you haven't already guessed, these are caused by shot pellets that escape from a weakly crimped cartridge, roll down the tube, and are then "ironed into" the steel when the cartridge they escaped from is fired.

The scenario goes like this:

A weakly crimped cartridge is placed in the left barrel.
Shooter fires the right barrel and recoil opens the crimp of the cartridge in the left barrel, allowing some shot to escape.
The shooter then fires the left barrel (as in clays doubles), and the remaining shot and wad iron the escaped pellets into the steel, creating "pimple bulges."
The shooter notices them sometime later...

This is an especially costly fix in O/U guns since ribs must be removed.

Moral of the story: Toss those soft-mouth hulls and save yourself some grief!