Markron Custom Bullet And Primer Sealer - An unsealed primer pocket joint invites moisture contamination resulting in misfires and shortened cartridge storage life. Makron bullet and primer sealer completely seals and waterproofs cartridge primers, shot shell primers, bullet case joints and off the shelf, unsealed, factory ammuntion for 100% firing consistency and extended cartridge storage life including up to 30 days total water submersion! Markron primer sealer has passed rigorous military testing and is used by U.S. Armament Manufacturers as their waterproofing sealer of choice. One 1/2 OZ Bottle Seals Approx 1000 Rounds; Does Not Effect Muzzle Pressure,Velocity, or Accuracy ; Fast Drying ; WaterProofs; Cartridge and Shot Shell Primers; Waterproofs: Rifle Primers and Handgun Primers; Waterproofs: Cartridge Case Joints; Waterproofs: Black Powder Nipples ; Perpetual Cartridge Storage Life ; Fast, Simple, Easy To Use; Up To 30 Days Total Water Submersion;