I’ve seen a 4 gauge English single barrel shotgun up close (or 4 bore as they would say). It was a muzzle loader and designed to fire a 4oz lead ball, not small shot. Impressive weapon, and I would be glad to watch someone else fire it.
A 4oz lead ball... We often refer to projectiles in “grains.” For instance, the standard military .45 auto round uses a 230 grain bullet. A terrific bullet for hunting bear is the 300gr Sierra JFP. 300 grains. There are 437.5 grains in an ounce. Which means the 4oz projectile weighs in at 1750 grains!
No thank you.
Mark