.22 Standards vs Subsonic, are standards also subsonic?

**Antlion** · 14-09-2019, 10:22

Some time back I saw a video where the host explains most .22 ammunition sold as "standard velocity" are in fact running at subsonic velocities through most rifles and "Sub sonics" are a marketing term , but they are a tad slower and usually have a HP bullet. If I take CCI as an example. Advertised velocities.
CCI Standard velocity RN-1070fps
CCI Sub sonic HP- 1050fps.
Are both not running under the speed of sound or am I missing something?

**treeman** · 14-09-2019, 13:04

go to this site and you can work out the speed of sound at a given tempreture
https://www.weather.gov/epz/wxcalc_speedofsound

and hear includes altitude
https://www.engineeringtoolbox.com/e...ir-d_1534.html

**nkosi** · 14-09-2019, 14:06

Ja, in the old days standard velocity for a 40 gr .22 lr normally meant something between 1150 - 1250 fps or more.

Now that velocity range has been re-branded as high velocity and subsonic as standard velocity (1040 -1080 fps generally depending on brand).

Subsonic now means slower than that velocity range.

Have to love the marketing men.

**Ds J** · 14-09-2019, 15:51

Speed of sound is generally given as 1125 fps.

That means standard ammunition was just at or above the speed of sound.

If they sold sub sonic at 1080fps, and it was shot on a hot day from a slightly longer barrel, the producing company would have gotten an angry call: "Hey, your subsonics are supersonic!"

Thus maybe they changed it?

And going through the sound barrier has an effect on accuracy, or not? That could be another reason for keeping speed slightly down.

**geopat** · 15-09-2019, 02:52

Not sure about today's ammo but sqartklip standard velocity was usually sub sonic but every now and then my brno. 22 used to get one that cracked always.gave me a fright as I was always using a supressor

**A-R** · 15-09-2019, 13:30

Some SV rounds will indeed be subsonic most of the time from certain barrels. Others may exceed the sonic limit occasionally. It depends on may factors, weather and barrel included.

Most "Pistol Match" rounds seem to run subsonic from rifle barrels.

**Dumbluck** · 15-09-2019, 14:03

Yes both are sub sonic, from what I've read sub sonics have a cleaner burning powder to not foul up your silencer as much. I can't say I have tested this.

I've been shooting CCI sub sonics with good accuracy but I have Norma match ammo still to test.

For the NRL22 match (course of fire set out in yards at 25,40,50,60,75,90,100) I zero'd for 50 yards, and held 1cm low for 25,40 centre for 50,60 and held over for 75,90,100 with good success using a old duplex reticle and data from strelok, most brands of ammo are listed.