The term “Big Bore Airguns” generally refer to airguns that are .30 caliber and larger. Production big bores are currently available in .30 (7.62mm), .35 (9mm), .40 (10mm), .45 (11.43mm) and .50 (12.7mm) calibers.
These airguns are normally precharged pneumatic (PCP) airguns which use an onboard air reservoir of highly compressed air to propel the projectile. Air reservoir max pressure varies by model. Most carbon fiber air reservoirs have a 4500 psi max pressure. To put that in context, most home air compressors have a 35 to 60 psi working pressure.
Big bore airguns provide the power necessary for big game hunting. In most cases, they are able to shoot a wider range of projectiles. Projectiles include standard diabolo pellets, round ball, and cast lead. Cast lead can be conical slugs that you might see shot from a muzzle loading rifle, wadcutters and hollow points. Some big bores of .35 caliber and larger can deliver specially designed arrows. These arrows are similar to crossbow bolts, but can deliver hunting broadheads up to 500 fps with great accuracy.
Big bores deliver a great amount of muzzle energy. One up coming .50 caliber model boasts up to 700 fpe, while most big bore airguns deliver between 150 and 400 fpe. Big bore airguns, combined with proper shot placement, allow airgun hunters to harvest feral hogs, deer, black bear, mountain lion, and other large game.