.22 ammo inaccuracy - Short, CB, subsonic

[jpwilly]

I've read that subsonic rounds are inherently more accurate than supersonic rounds, on the basis that they do not breach and re-enter the sound barrier, causing

Does this hold any validity?

Yes

I recently went out and purchased some .22 cal 780fps (iirc) CCI CB ammo to try and test this theory. While I was able to dime-hole (er, a bit smaller, actually) the targets I was shooting at 25 yards with Remington Game Load and CCI Mini Mag, I spent the better parts of an hour and 100 rounds of the CCI CBs missing the 4"x4" paper targets I was using. At first I thought it was a pressure charge issue, with the bullets simply not having the same trajectory (it took me a while to figure out precisely where the bullets were going, unfortunately). That proved to be un-true, and the bullets were simply impacting in a much larger radius (about 8" @ 25yds).

So you picked one of the most inaccurate subsonic ammos you could find for your test...and in your own words:

I went back to shooting 'bulk' and the CCI ammo afterwards to verify that it wasn't the gun. I was still able to shoot the brass 'tops' off shotgun hulls at 50 yards, and the paper targets looked the same.

So what's the scoop here? I'm shooting with a CZ 452, by no means a 'crap rifle'. Could it be a rifling twist issue? Or my rifle simply not 'liking' the CCI CB Short ammo? Or something to do with the rate of twist? I find it hard to believe there'd be that much inherent inaccuracy in a commercially loaded round.

THE SCOOP = Subsonic MATCH grade ammo (Eley, SK, Wolf etc) and subsonic CCI CB Caps are worlds apart in the accuracy department.

If it is in fact that the CB Shorts are just bad/inaccurate, are there any other subsonic rounds I might be able to try which have shown to be accurate, in your experience?

Bingo, try some Wolf Match Target, CCI Green Tag, Eley etc for example. CB Caps were designed for shooting galleries back in the day and for indoor shooting not for accuracy.