Im thinking about purchasing an old (but very nice) cooey .22lr bolt action. The main reason i plan to purchase it is to have a .22 repeater i can run anything i want out of. The problem is that i really enjoy shooting subsonics, and i am concerned that the cooeys 24" barrel may possibly cause a squib. The lowest velocity rounds i'll be running are cci quiets and cb short; both hovering about 710 fps. Is this enough velocity to make it through such a long barrel? And will the weight difference in the 40 and 29 grain bullets play a factor? Scientific, personal, and anecdotal evidence are all accepted .

Most all standard velocity ammo is subsonic. I know some brands of cb shorts ( Aguila comes to mind) state not to use in rifles due to the squib issue. For cci you might contact them to verify but since the cci use powder ( Aguila only priming compound ) I would imagine you are ok. Lots of small bore shooters use cci standard so I know you are ok there

I shoot CB caps from my Remington 24" pump action w/o any problems. Quiet is an understatement.

I think ill give it a go; and just be very careful to listen for the small odd 'pop' the first 100 rounds or so with cb's;

CCI standards are beautiful

I've heard of people shooting 40gn subs out of long barrels (26+ in). I've heard them say it's like suppressor quiet due to the drop in pressure. Not sure if this is true or not, saw it on a random forum.

I shot hundreds of cci cb shorts and longs out of my 22 inch marlin 81. The report of both was just a little louder than my co2 air rifle, with the cb longs being just a little quieter.... fwiw

Back in my youth I had a Winchester 67 single shot and seem to recall the barrel was around 24 inches long. Used to shoot cb shorts and cb longs as well as standard velocity ( or as a kid and later a poor college student- my college did not care I had a 22 rifle in my car- would not try that today!) and never had an issue with the bullet clearing the barrel. And walking into the woods near the college could set up some empty cans and shoot and it did not disturb anyone.

I've shot several bricks of Aguila Colibri through my 24" Rossi Winchester 61A clone. That's the slowest ammo I've ever seen and it was fine.

It's quieter, but not that quiet. That's what I hunt with because it spooks the game in the area less, but it's not even close to what even my pistols sound like with the suppressor on. Not even the CCI Quiet or the CB's are as quiet as a suppressor, not even in a 24" barrel. The only ammo I've shot that is "suppressor quiet" is the Aguila Colibi and Super Colibri. They are "suppressor quiet" in everything, but they have so-so accuracy and are only a 29gr bullet moving at 600fps. I have used them to kill rats in the basement, but that was it. I wouldn't task them with any job you wouldn't use a .22 pellet rifle for.