![]() I took them out today to run through the chronograph and see how they would group but conditions were less than ideal with misty rain and a bit of wind. I still have a small supply of the Aussie subs which are in the white packet then later a blue box, the USA made ammo comes in a plastic container with the slide lid. I bought a box the other day to compare the two and thought I would post up the results here so here we go. Australian made Winchester 40 gr subsonic is no longer being made but American Win 40gr sub is available.īy all accounts and reading about the American ammo it appears to be suffering from a bit of quality control and most people are complaining that it doesn't compare with the old Aussie round. With all the ammo shortages these days its hard to get the ammo you want sometimes. īut a 47" 22 rifle are quiet with 0.65 gr of powder. the bottom line is that a 25" 22 caliber barrel will be quiet with up to 0.45 gr of powder. Sparing you all the details of my low sound wildcats, 12 foot long guns, and experimenting. 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, Someone calculated that the threshold was one atmosphere above ambient. I knew a little about spherical sound waves, but not enough to calculate the threshold. I had taken EE360 Accousitcs at the Univ of Wash from Rubens Sigelmann when he was developing ultra sound technology. He said the difference was the threshold of super sonic gas escapement. Professors did not have the answer, but a gunsmith, Randy Ketchum, with two year of college did. The 24" made three distinct sequential sounds 1) the firing pin, 2) the report from the muzzle, and 3) the bullet striking the target. 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. 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. 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. 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. HV really only gets inconsistant if you are shooting it past the point of where it drops out of super sonic speed. but at around 100yards, just about everything starts messing around with rimfire ammo. 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. 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. of course the slower stuff will drop more than HV, but generally be more consistant / accurate at any distance. 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. 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. 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 closest thing i've found that matches up with the print on the box is. 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. ![]() 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). Technically, match / standard velocity type ammo is subsonic as it's below the speed of sound from muzzle to target.
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