Well at least here in Texas you can use an air gun for hunting
here's the Regulation for Air Guns and air Arrow guns
Air Guns and Arrow Guns
Alligator, game animals, furbearers, squirrels, and non-migratory game birds (
except eastern turkey) may be hunted with air guns and arrow guns provided:
- alligators, bighorn sheep, javelina, mule deer, white-tailed deer, pronghorn, and turkey (except eastern turkey) may be taken only with pre-charged pneumatic arrow guns, or pre-charged pneumatic air guns.
- pre-charged pneumatic air guns must fire a projectile of at least .30 caliber in diameter and at least 150 grains in weight with a minimum muzzle velocity of 800 feet per second or any combination of bullet weight and muzzle velocity that produces muzzle energy of at least 215 foot pounds of energy.
- squirrels, pheasant, quail, and chachalaca may be hunted with air guns that fire a projectile of at least .177 caliber (4.5mm) in diameter producing a muzzle velocity of at least 600 feet per second.
- arrows or bolts used with an arrow gun must conform to the same standards for projectiles for archery.
- arrow guns may not be used to hunt deer or wild turkey during archery season