Wrong about Arkansas but here is the regulations right out of the hunting guide book for arkansas.
All modern guns may be used for deer hunting during modern
gun season with the following exceptions. You may not use:
• buckshot in a .410 shotgun.
• shot smaller than No. 4 buckshot in any shotgun.
• rimfire cartridges, military or full metal jacketed ammunition.
• any centerfire rifle or pistol smaller than .22 caliber.
• handguns with barrels shorter than 4 inches.