Shooting from a Marlin 22 bolt rifle with a 22" inch barrel which round would be quieter.  22LR, 22Short, 22 subsonic.  I tried all three at the range and could not see any difference without instruments to measure decibels.  What are your thoughts?  Thank you, Mike

Try some Aguilla -I had issues with CCI not staying subsonic in a rifle.


BTW - if you are not running a can, you won't really notice the difference

22 CB's and and 22 shorts are noticeably quieter out of my 16" Henry trapper lever gun. The CB is quieter than the short but the short is noticeably quieter than the LR. Not by much but it is a noticeable difference.

+1
CB's are going to sound like a pellet gun, probably quieter with the 22' bbl

P

I've shot l.r.'s and shorts out of a 552 speedmaster and with shorts, the noise of the bolt seems about as loud as the shot.

From my experience with an old Marlin 25N (22" bolt action), rated from quietest to loudest:

CCI .22 CB Long: actually sounds quieter than a pellet gun,  you can hear the firing pin drop, but accuracy kinda sucks (2" at 25 yds)
CCI CB Short: actually slightly louder than the Long, with accuracy virtually non-existent
Remington 22 LR Subsonic: still very quiet  (as loud as high-power piston airgun), but very inconsistent with many FTF and fliers
Aguilla 60gr SSS - the WHACK of the projectile hitting the bullet trap is louder than the report, good accuracy (1" at 50 yds with occasional flier)
CCI Standard Velocity - louder, but still subsonic  (no crack), good accuracy (.75" at 50 yards)
Wolf Match Target  - even louder, probably transsonic, excellent accuracy (.5" at 50 yards)
Anything 22 LR high-velocity (loud supersonic crack)
CCI Stinger (even louder CRACK, makes your ears ring)

With that in mind, my favorite low noise round is the CCI Standard Velocity, which combines good accuracy with low report.

Strange, the CCI CB long and short are the same round except for the case length.  The powder charge and velocity are identical.

Aguila makes the Colibri and Super Colibri, which should be the quietest of them all.  There is no powder, only the primer.