Hammerhead Classic Barrel Fin Sizer Pistol The outside diameter of this

The outside diameter of this barrel is 7/8-inch

Features Include: - 13" Barrel Rifled- Micro-honed- Counter-Bored- Reverse Ported- Auto Cocker Thread  (Gun End)- 22MMX1 Thread (Muzzle End)Accepts Shrouds and Hammerhead Muzzle Breaks

Optical magnification: 1X Red-Dot

While this clear portion disappears into your magwell

the stock guide may be too tight

Hammerhead Classic Barrel Fin Sizer Pistol The outside diameter of thisHammerhead Fins (Sizers) are designed to match the ball size to the barrel. The type of ball, weather and manufacturers tolerances can all have an affect on a paintball size. To optimize your barrel performance it makes sense to have the right sizer for the ball used that day. Hammerhead Fins are 2" in length which is an optimal length based on the amount of air pressure that occurs during the first two inches of a ball being shot out of a paintball