Vector Optics Snap Caps Rifle .300 AAC Blackout 6 Rounds/ Pack w/ Sling Red. A snap cap is a device which is shaped like a standard fire-arms cartridge but contains no primer propellant or projectile. Snap cap is designed to be a fake cartridge from the very beginning. It serves the same function as a dummy round but different in that a dummy is usually made from a real cartridge with its propellant and primer removed (still has the projectile and the casing). Specifications for Vector Optics Snap Caps w/ Sling: Manufacturer: Vector Optics Caliber: .300 AAC Blackout Fabric/Material: Silicon Aluminum Number of Rounds: 6 Gun Type: Rifle Color: Red Condition: New Finish: Anodized Features of Vector Optics Snap Caps w/ Sling Totally safe Functions just like real ammo - without the noise Offers versatility: training storage testing practice Thousands of dry fires without damage Package Contents: Vector Optics Snap Caps w/ Sling Vector Optics SCSC-03: Snap Caps Rifle .300 AAC Blackout 6 Rounds/ Pack w/ Sling Red