Velocities of Subsonic & Suppressor Ready .22 Cartridges Fired in Pistols

U.S.A. –-(AmmoLand.com)- Published velocities for .22 Long Rifle cartridges are generally available for rifle-length barrels. Finding the velocities for pistol-length barrels is more difficult.  Searches on the Internet did not yield results for several subsonic .22 Long Rifle cartridges. This article shows velocities measured from three pistols for five different cartridges.

Velocities in a particular barrel length can vary with individual barrels. Some barrels are smoother than others. Even the temperature of the cartridge when the round is fired can make a measurable difference. To see the differences for pistol length barrels, three handguns were used because they were handy and were threaded for suppressors.  Using a suppressor can affect velocity, but the amount is usually small and can be in either direction. Different lots of the same ammunition may have differences in velocity, usually small.

The three pistols used were a Kel-Tec CP33 with a 5.5-inch barrel, a Taurus TX22 with a 4.1-inch barrel, and a Kel-Tec P17 with a 3.93-inch barrel.

The cartridges tested were, in order of published velocities:

• CCI 40 grain Quiet .22 Semi-Auto – 835 fps
• Aguila 60 grain SniperSubSonic – 950 fps
• Federal American Eagle 45 grain suppressor – 970 fps
• Winchester 45 grain Super Suppressed – 1060 fps
• CCI Standard Velocity – 1070 fps

Velocities shown in the chart are the average for five shots. The temperature varied form 56 to 76 degrees Fahrenheit.  Velocities were measured 10 feet from the muzzle with a Caldwell Chronograph G2. Five shots should be sufficient to give a good idea of pistol velocities from 4 and 5.5-inch barrels. Differences between the 4.1-inch and 3.93-inch barrels were expected to be small.

As can be seen from the chart, all of the rounds tested were reliably subsonic from the pistols tested. While the speed of sound varies with temperature, even at 40 degrees below zero, the speed of sound is above 1000 fps. As the temperature rises, so does the speed of sound. At freezing, it is 1087 fps. At 70 degrees Fahrenheit, it is 1128 fps. At 100 degrees F, it is 1159 fps.  Atmospheric pressure has little effect on the speed of sound. As relative humidity increases, there is a slight increase in the speed of sound, just a few fps. It is expected few shots will be fired from a suppressed .22 pistol at temperatures lower than 40 below zero.

As a purely subjective measurement, the quietest ammunition, using a suppressor, was the CCI Quiet .22 Semi-Auto. The next quietest was the Federal suppressor American Eagle 45 grain load. The CCI Standard Velocity seemed a little louder.  The Winchester 45 grain was a bit louder yet. The Aguila 60-grain SniperSubSonic seemed to be the loudest. It appeared to contribute considerable noise from the chamber area, perhaps because of the short case.  With a suppressor, it was much quieter than fired without a suppressor. Subjectively, it seemed to be the noisiest. This writer suspects it would do best out of manually operated rifles.

The average difference in velocity between the 5.5″ barrel and the 3.93″ barrel, looking at all five cartridges, was only 25 fps. The 4.1-inch barrel was in between.

The 60-grain bullets of the Aguila need a faster twist than 1 in 16 inches to stabilize properly. The Kel-Tec CP33 and P17 both have 1 in 14 twists, which seem to stabilize the long bullet a little better. The new Taurus Compact TX22 has a 1 in 10 twist, which should stabilize the 60-grain Aguila load. It has a 3.6-inch barrel, so velocities of about 750 to 760 fps would be expected out of the shorter barrel with the 60-grain bullet.

About Dean Weingarten:

Dean Weingarten has been a peace officer, a military officer, was on the University of Wisconsin Pistol Team for four years, and was first certified to teach firearms safety in 1973. He taught the Arizona concealed carry course for fifteen years until the goal of Constitutional Carry was attained. He has degrees in meteorology and mining engineering, and retired from the Department of Defense after a 30 year career in Army Research, Development, Testing, and Evaluation.