Winchester Ammunition introduced a new .22 LR round at the recent SHOT Show. The new M-22 Subsonic is built specifically for semi-automatic pistols and rifles. As the name suggests, the new rimfire load operates below the speed of sound from all barrel lengths.

Winchester Ammunition uses a 45 grain lead round nose bullet with a black plating. Using the slightly heavy for caliber bullet allowed the company to keep velocities down while still developing respectable energy levels. In fact, Winchester Ammunition states the new load produces a muzzle energy equivalent to their supersonic 36 grain bullet loads. Winchester did not provide a velocity measurement for the new load.

According to the company, the rounds work well in suppressed firearms. Additionally, the company states the load is just as reliable and is relatively quiet when shot from unsuppressed firearms. Winchester Ammunition states that when shot from an unsuppressed rifle, the M-22 Subsonic produces a sound pressure level of 129 dB. The company’s testing showed that supersonic loads produced 138 dB from the same rifle. With the addition of a suppressor (type not identified by Winchester,) the company states the sound pressure level drops to a much safer 116 dB.

The company already makes an M-22 .22 LR round, but the existing load is supersonic: 40 grain bullet at 1,255 fps.