Smith & Wesson M&P15 Carbine .300 Whisper 16" Melonite Barrel Realtree CAMO 10 Round Magazine Law Enforcement Only

The 300 Whisper was developed in the 1990s by J.D. Jones of SSK Industries. Based on the 223 Remington (or 221 Remington Fireball) case necked up to 30-caliber, it was developed primarily as a subsonic round intended for military use in suppressed firearms. The 300 Whisper is dimensionally almost identical to the later 300 AAC Blackout, but the Whisper is standardized by the European body, CIP, while the Blackout is standardized by the American body, SAAMI. 300 Whisper functions in standard AR15/M16 magazines, and any firearm chambered to 223 Remington can generally be converted to 300 Whisper by simple rebarreling. Subsonic ammunition uses a heavy 220-grain bullet at 1040 fps; high-velocity loads are similar in performance to the 7.62x39, thus the 300 Whisper is capable for deer-size game at shorter ranges. — Craig Boddington