I am happy to add to the mis-information since I have been too lazy to chrono any of my 22's. I have an old Remington Mod 41 target master with a 27" bbl. When shooting tgt velocity, subsonic 22lr ammo it sounds suppressed. Very quiet. I have an Ithaca lever action with a 16" bbl. It cracks no matter what ammo I used. Most of my rifles have bbls that range from 20" to 28". It is interesting if a little off topic that when working with Tony Purdy a couple of years ago on a solution for tuning a barrel using the old bbl length method, we arrived at an "Ideal" length of 22 3/4" as a so-called ideal length for 22lr ammo of about 1065 fps for minimizing the bbl harmonic vibrations at the muzzle. Then I measure two of my best shooting repeaters the Anschutz 1451 and Winchester 52 (modified to carbine length) and the Annie is 22.5" and the Win is exactly 22.75" from bolt face to muzzle crown. Maybe those are coincidental as two others the Anschutz 54 SM and the Vostok CM-2 are each closer to 28". Annie is 27.6" and Vostok is 26.75" and those are both extremely accurate as well. Then another the Ishmash Biathlon Tgt is 19.7". If I were not so lazy, I could put this question to bed.
Test data above would suggest that a small gain of about 27 to 33 fps might be had from 16" to 20", but since those are two guns with two chambers, there are other variables which also affect velocity. Still that data shows about a 2.5% gain. Not much difference. Unless the longer bbl is helping with a longer sight radius on iron sight guns, my thoughts are that the added weight out weighs (literally) the benefits once the bbl gets much longer than 22". Just remember that if you are shortening the bbl, it will mess with the harmonics. Do not assume that it will shoot better or worse afterward. Just different. Add on the weight of a suppressor and it just might shoot better? or worse... But almost always different. I saw a huge change in one rifle just by changing from a receiver mounted modern 24x scope to a vintage bbl mounted 24x scope. Nothing else changed and yet the gun grouped much better with the same lots of ammo. How? The optics tube was bridging the bbl for much of its length making the assembly stiffer in the vertical plane and restricting the vibrations at the muzzle. Result less movement of the muzzle and less dispersion of the shot as it exits the muzzle. Leading to tighter groups. Now, if this is true all the time?, why are we not seeing Olympic tgt rifles that are equipped with a truss bridge like stiffner installed along the length of the bbl.'s?? Maybe it is true randomly in that I just hit a lucky arrangement creating a "Shooter". If I tried the same thing on another gun it might shoot worse. Not enough data to reach a conclusion. Just lots of questions.
Irish
