Here’s a simple tip for hollowing out tiny machine-gun barrels: Using a brand-new No. 11 blade, lightly score an X at the muzzle. Next, twirl the blade tip at the center of the X. After just a few rotations, a cavity will form. That is a good starting point; continue with the blade tip or switch to a pin vise and deepen the cavity to create the illusion of a hollow barrel.

Tip submitted by:
Woodrow AnselenCorona, Calif.