Markron's Custom Bullet and Primer Sealer is a fast-drying, easy-to-use waterproofing agent for primer pockets, bullet-case joints and black-powder nipples. It gives your cartridges unlimited storage life and is guaranteed to provide complete moisture lock-out for up to a 30-day water submersion. Will not affect pressure, velocity or accuracy. One bottle seals up to 1,000 rounds. .5 oz. Easy-to-use waterproofing agent Gives your cartridges unlimited storage life Will not affect pressure, velocity or accuracy