HSM Ammunition Varmint .223 Remington 55 Grain Flat Base Spitzer Brass Cased Rifle Ammo 20 Rounds. Accuracy again is at the apex of consideration when each component is chosen. Specifications for HSM Ammunition Varmint .223 Remington 55 Grain Flat Base Spitzer Brass Cased Rifle Ammunition: Manufacturer: HSM Ammunition Caliber: .223 Remington Number of Rounds: 20 Bullet Type: Flat Base Spitzer Bullet Weight: 55 grain Cartridge Case Material: Brass Muzzle Velocity: 3120 ft/s Application: Small Game Primer Style: Centerfire What is HSM Ammunition Varmint .223 Remington 55 Grain Flat Base Spitzer Brass Cased Rifle Ammunition good for? The manufacturer thinks that it is good for small game.HSM Ammunition HSM22354N: Varmint .223 Remington 55 Grain Brass Cased Rifle Ammo 20 Rounds