Seneca Double Shot .50 cal Double Barrel Shotgun Precharged pneumatic 244 cc air cylinder Two Smooth Bore Barrels Up to 5 good shots per fill 3000 psi fill Male Quick Disconnect Foster Fill Fitting On-board pressure guage Velocity up to 1130 fps with shotshells Velocity up to 425 fps with Air Bolts (170+ FPE) Velocity up to 600 fps with Round Balls (140+ FPE) Thread on chokes (Easily removed for use with Air Bolt or Slugs) Front bead sight (no rear sight) Optional 11mm dovetail scope rail to add optics Ambidextrous hardwood stock Rubber Buttpad Patent Pending Air Distributor allows a follow-up shot in less than 2 seconds Bore Diameter: 12.47mm Barrel Thread: 16.6x18 Choke Measurement: 12.4mm The choke reduces the inner barrel diameter from .494" to .486"