just wondering here about the speed of sound (about 1120fps in air) with some slight variation due to temp and humidity. my question is this-is the whole subsonic 22 ammo thing an advertising gimmick,as i suspect? most standard velocity ammo match and regular is rated at about 1040-1080 fps. so most normal 22 is already subsonic if my numbers are correct. i know cci and aguila make some real slow stuff 700ish. also,i am told,that that is the reason a lot of 22 hi vel is rather inaccurate. becomes unstable when it goes subsonic. again i am told the same holds for any round crossing back below the barrier. input from anybody with the knowledge?
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speed of sound and 22lr "subsonic" ammo
- Thread starter mosin46
- Start date
Cci standard ammo is subsonic (unless it's really cold out). Quite frankly im not sure why they make ss rounds other than that.
When i shoot standards from my 10/22 the majority of the noise comes from the action cycling and the round hitting the target.
Most actual sub sonic ammo lower than that will have trouble cycling in a semi auto. The really slow stuff works awesome in bolt actions. I really cannot imagine it much quieter than mine aside from an action not moving.
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When i shoot standards from my 10/22 the majority of the noise comes from the action cycling and the round hitting the target.
Most actual sub sonic ammo lower than that will have trouble cycling in a semi auto. The really slow stuff works awesome in bolt actions. I really cannot imagine it much quieter than mine aside from an action not moving.
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Winchester and Eley subsonic are both pretty quiet with absolutely stunning accuracy. I watched the video referenced above and it seems pretty unscientific. SS is about all I use in any or my rifles or pistols, mostly because my guns like them (accuracy wise). They cycle just fine.
I have used eley in the past and really liked them. Great accuracy but for me, not enough to justify the price over cci
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I cant tell any difference sound wise between CCI SV and CCI subs, with or without the sparrow on the end of my 22/45 lite. Havent tried it yet out of my savage FVSR yet.
"just wondering here about the speed of sound (about 1120fps in air) with some slight variation due to temp and humidity"
FWIW, it is not a slight variation, Mach is totally temperature dependent. If you add 1060 to your outside air temp (OAT), you will get Mach for those conditions within 2-3 fps. 1058 + OAT for lower temps and 1060 + OAT for higher temps. You can throw out humidity. In a very wide temp range and using 0-100% humidity, I think Mach changes by a percent or two.
This is the reason for knowing the conditions the manufacturers measured the muzzle velocity (mainly barrel length and OAT). The closer your shooting equipment and conditions are to theirs the better, and vice versa.
The transonic region btwn .8-1.2M has the highest drag changes as the round transit this area. Generally speaking, either side of this will be "clean" air with generally consistent ballistic performance.
FWIW, it is not a slight variation, Mach is totally temperature dependent. If you add 1060 to your outside air temp (OAT), you will get Mach for those conditions within 2-3 fps. 1058 + OAT for lower temps and 1060 + OAT for higher temps. You can throw out humidity. In a very wide temp range and using 0-100% humidity, I think Mach changes by a percent or two.
This is the reason for knowing the conditions the manufacturers measured the muzzle velocity (mainly barrel length and OAT). The closer your shooting equipment and conditions are to theirs the better, and vice versa.
The transonic region btwn .8-1.2M has the highest drag changes as the round transit this area. Generally speaking, either side of this will be "clean" air with generally consistent ballistic performance.
PMC Moderator (no longer made but a ton of it showed up locally during the panic) is listed at 1005fps and GemTech is down there as well. Both work semi autos fine. Of course, to find out what it is really doing in your rifle you have to chrono it. Of course, you can make a crude chrono with a vise, some levels, an accurate way to measure both meters and milimeters, and a calculator. I've seen other shooters with the same model guns report numbers from a chrono - the one that sticks out is CCI SV out of a mossy 44 w/ 26" tube clocked at 990fps.
technically, match / standard velocity type ammo is subsonic as it's below the speed of sound from muzzle to target. so anything under that 1080 / 1120ish print on the box is really subsonic as it never goes past the speed of sound (depending on extreme environmentals).
IMO a fine example of subsonic gimmic on the box is remington subsonics, through a chrony i've recorded the same FPS 10 feet from muzzle as wolf extra & match, yadda yadda.
the closest thing i've found that matches up with the print on the box is .22 mag, hornady 30gr.
the truely really slow / quiet stuff should have a specialty type branding on it including the CCI quiet, rem cbee, CCI cb, and the like that have a majorly reduced powder charge, or even no powder at all and relies on the priming agent to propel the bullet. the trueist of labeling is the aguila with super subsonic designation, which in my opinion is like a generic term that describes CCI quiet, rem cbee, CCI cb both in FPS and sound, getting below 700 fps 10 ft from the muzzle.
over the travel of the bullet, you'll have more stability from muzzle to target as there's no transonic stuff going on over any of the trip there. of course the slower stuff will drop more than HV, but generally be more consistant / accurate at any distance. the specialty type as mentioned above has it's drawbacks when launched at longer distances, but within 75 yards and depending on if your rifle likes them, work pretty good when trying to be discrete.
humidty - as far as FPS at the muzzle it isn't much of a concern to me, until i start getting out about 100 yards - then the "thicker" air starts to actually start showing up POI differences. but at around 100yards, just about everything starts messing around with rimfire ammo.
HV really only gets inconsistant if you are shooting it past the point of where it drops out of super sonic speed. in other words, if you are using velocitors, mini mags, or just plain ol' HV there shouldn't be all that bad of groups (again depending if your rifle likes them and bullet design) if you are staying within that distance of going transonic. keep in mind these types are also produced in a more "pump it off the line and out the door" bulk type manufacturing, where even lower grade match ammo gets at least a little more attention to detail and manufactering machinery calibration to at least "pump out" a little better quality product.
given the choice, i wouold and do stay with a standard or match velocity in the 700-1050 to help take out most of the variables over longer distances and temperature swings.
IMO a fine example of subsonic gimmic on the box is remington subsonics, through a chrony i've recorded the same FPS 10 feet from muzzle as wolf extra & match, yadda yadda.
the closest thing i've found that matches up with the print on the box is .22 mag, hornady 30gr.
the truely really slow / quiet stuff should have a specialty type branding on it including the CCI quiet, rem cbee, CCI cb, and the like that have a majorly reduced powder charge, or even no powder at all and relies on the priming agent to propel the bullet. the trueist of labeling is the aguila with super subsonic designation, which in my opinion is like a generic term that describes CCI quiet, rem cbee, CCI cb both in FPS and sound, getting below 700 fps 10 ft from the muzzle.
over the travel of the bullet, you'll have more stability from muzzle to target as there's no transonic stuff going on over any of the trip there. of course the slower stuff will drop more than HV, but generally be more consistant / accurate at any distance. the specialty type as mentioned above has it's drawbacks when launched at longer distances, but within 75 yards and depending on if your rifle likes them, work pretty good when trying to be discrete.
humidty - as far as FPS at the muzzle it isn't much of a concern to me, until i start getting out about 100 yards - then the "thicker" air starts to actually start showing up POI differences. but at around 100yards, just about everything starts messing around with rimfire ammo.
HV really only gets inconsistant if you are shooting it past the point of where it drops out of super sonic speed. in other words, if you are using velocitors, mini mags, or just plain ol' HV there shouldn't be all that bad of groups (again depending if your rifle likes them and bullet design) if you are staying within that distance of going transonic. keep in mind these types are also produced in a more "pump it off the line and out the door" bulk type manufacturing, where even lower grade match ammo gets at least a little more attention to detail and manufactering machinery calibration to at least "pump out" a little better quality product.
given the choice, i wouold and do stay with a standard or match velocity in the 700-1050 to help take out most of the variables over longer distances and temperature swings.
I've shot lots of subsonic that is just as loud as regular stud. Not even sure why its marketed as sub
I shoot bulk SS out of a pistol and it stays subsonic.
Out of my 10/22 I shoot the CCI Subsonics 1050fps and
once in a while i'll get a crack.
Out of my 10/22 I shoot the CCI Subsonics 1050fps and
once in a while i'll get a crack.
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Few years back PMC canceled the Moderators but did bring the moderators back again . ( PMC & Aguila superSE ) Sub vel. Ammo , Are also one in the same As they are subcontracted & made by Aguila for PMC .
Moderators/SuperSE have shot pretty good through most my stuff over the years . It's not Match tight but pretty consistent for plinking , The Parfine lube is pretty low quality but if you re-lube with your own stuff you can squeeze a little more accuracy out of them . what sucks and reality is they are a true .99 cent box .22 ammo but that is what you get these days .
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I liked 22s that sounded like BB guns.
I became curious 20 years ago as to why a 22" barrel was so noisy and a 24" barrel was so quiet with Remington CB Longs.
The 24" made three distinct sequential sounds; 1) the firing pin, 2) the report from the muzzle, and 3) the bullet striking the target.
The 22" barrel made just one loud BLAM!
I started asking around.
Professors did not have the answer, but a gunsmith, Randy Ketchum, with two year of college did. He said the difference was the threshold of super sonic gas escapement.
I had taken EE360 Accousitcs at the Univ of Wash from Rubens Sigelmann when he was developing ultra sound technology.
I knew a little about spherical sound waves, but not enough to calculate the threshold.
I got some help on usenet rec.crafts.metalworking.
Someone calculated that the threshold was one atmosphere above ambient.
That made sense with the peak of the wave at 2A and the trough of the wave at 0A, which is the threshold of cavitation, [the most energy we can acoustically transmit in a medium]
Sparing you all the details of my low sound wildcats, 12 foot long guns, and experimenting.... the bottom line is that a 25" 22 caliber barrel will be quiet with up to 0.45 gr of powder [CCI CB Short].
But a 47" 22 rifle [these are not easy to build] are quiet with 0.65 gr of powder [ Polish surplus target short].
What should you know about 22s that sound like BB guns?
You have to aim for the brain.
I became curious 20 years ago as to why a 22" barrel was so noisy and a 24" barrel was so quiet with Remington CB Longs.
The 24" made three distinct sequential sounds; 1) the firing pin, 2) the report from the muzzle, and 3) the bullet striking the target.
The 22" barrel made just one loud BLAM!
I started asking around.
Professors did not have the answer, but a gunsmith, Randy Ketchum, with two year of college did. He said the difference was the threshold of super sonic gas escapement.
I had taken EE360 Accousitcs at the Univ of Wash from Rubens Sigelmann when he was developing ultra sound technology.
I knew a little about spherical sound waves, but not enough to calculate the threshold.
I got some help on usenet rec.crafts.metalworking.
Someone calculated that the threshold was one atmosphere above ambient.
That made sense with the peak of the wave at 2A and the trough of the wave at 0A, which is the threshold of cavitation, [the most energy we can acoustically transmit in a medium]
Sparing you all the details of my low sound wildcats, 12 foot long guns, and experimenting.... the bottom line is that a 25" 22 caliber barrel will be quiet with up to 0.45 gr of powder [CCI CB Short].
But a 47" 22 rifle [these are not easy to build] are quiet with 0.65 gr of powder [ Polish surplus target short].
What should you know about 22s that sound like BB guns?
You have to aim for the brain.
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It is when the round goes transonic, the somewhat violent transition from supersonic to subsonic that will effect accuracy. If a 22LR is only going supersonic for less than 50 yards, what are the benefits of being supersonic when you will sacrifice some accuracy? If you create ammunition that is subsonic at the muzzle, you can greatly increase its accuracy and consistency. Due to the somewhat anemic performance of the 22LRs design, many ammo manufacturers have realized subsonic 22LR ammunition is more accurate and have capitalized on the marketing of being subsonic. As you mentioned, there is 22LR ammo out there that may be subsonic depending on elevation that is not listed as such.
Kirk R
Kirk R
