Gemtech, famous for making quality suppressors, also sells their own line of subsonic .22LR ammunition through their online store.
SPOILER ALERT: IT ROCKS!
Gemtech advertises the velocity of their 42 grain round nose bullets as 1020 FPS out of a rifle (the speed of sound is 1116 FPS at sea level). As a comparison, CCI’s Mini-Mag ammunition is advertised as 1235 FPS out of the muzzle, and 1092 FPS at 50 yards. Yes, the Mini-Mag is still going faster at 50 yards then the Gemtech’s muzzle velocity, but even with a suppressor there is no way to quiet the Mini-Mags supersonic crack. The Gemtech isn’t significantly slower, but it will be much quieter during its short flight because it won’t break the sound barrier. You still get plenty of squirrel killing power, but it is still very quiet when using a suppressor. If you aren’t going to be shooting with a suppressor, then by all means use ammunition with a higher velocity. You won’t hear the supersonic crack over the gunshot.
The only guns that I have fired the Gemtech subsonic .22LR ammunition through are an AR-15 with a CMMG brand .22LR conversion kit, a Ruger 10/22 rifle, and a Glock equipped with an Advantage Arms .22LR conversion kit. I have only shot each a limited number of times, but so far reliability has been 100%. Details follow.
AR-15 with CMMG brand .22LR Conversion Kit:
I have fired close to 200 rounds through a Daniel Defense AR-15 with a CMMG .22LR conversion kit and Advanced Armament Corporation’s M4-2000 suppressor attached. Reliability was 100%. The Gemtech ammunition was very quiet when fired through the full-size 5.56mm suppressor. Good times!
Advantage Arms .22LR Conversion Kit for Glock Pistols:
I have an Advantage Arms .22LR conversion kit with a threaded barrel mounted on a Glock 17 with an Advanced Armament Corporation’s Element II .22LR suppressor attached. I have fired 150 rounds through the gun without cleaning it. I haven’t had a single malfunction. It is very quiet.
High reliability + very quiet = LOTS OF FUN!
Gemtech receives this ammunition in limited batches. You can sign up on their website to be notified via email when they have it in stock. When you get the email you won’t have very long to order before all of the ammo is sold out again (because A-holes like me purchase large quantities). Get it when you can, and get a lot.