It’s been almost three years since I had Tom Klinger install a shorter (20”) 1:16 twist Shilen ratchet barrel with a match chamber on my Stevens .22.  I continue to get comments about muzzle noise & velocities & thought I’d share my thought process prior to having Tom rebarrel the rifle.  At the time I did a good bit of research on .22-barrel lengths.  My main goal was achieving a better balance when shooting offhand chickens.  Some prefer a heavy-barreled rifle indicating it doesn’t move around as much.  Due to old age & being in less-than-ideal physical shape, a lighter weight rifle is easier for me to control.  And, although I still shoot zero chickens now & then, my average chicken scores have improved.  Also, since I use a scope, barrel length is not an issue.
 
During the research I ran across the results of an experiment on barrel length vs. velocity.  Here's the results of shortening a Ruger 77/22 barrel in 2" increments: 28" 1095fps, 26" 1107, 24" 1119, 22" 1129, 20" 1138, 18" 1149, 16" 1157, 14" 1149 fps.  So, the average in the Ruger is approximately 5fps/inch.  And, as reported in other articles, .22LR barrels less than 16” or shorter will lose velocities.
 
Due to a good bit of experimenting out to 200yds. with several brands of ammo, I’ve concluded my rifle likes Eley 10X or Match (black box) rated velocities in the 1080fps range.  But that’s not the actual muzzle velocity of the rifle.  More on this later.  If you’ve wondered how Eley determines the lot velocity, following is the method: Once a lot is manufactured, four different test guns are used to test the lot in a 50-meter tunnel.  The rifles are all different ages (based on round fired) with different barrel lengths and chamber specs.  If all four guns shoot a lot well, the lot is labeled 10X.  If it shoots well in some of the guns and not others, it's labeled Match.  If it does not shoot that well in any of the guns, it's labeled Eley Team.
 
I mentioned above that my rifle likes Eley Match with a rated velocity in the 1080fps range.  If you wondered what the actual velocity was out of my rifle.  Using Eley Match rated at 1084fps, the muzzle velocity averaged 1148fps, about a 6% increase.

Continued on next post.
Wayne

FWIW @ 20” you’ve eliminated a lot of the benefit of the Shilen which is taper lapped and by design is made to end up 24”-26”,
Your referenced study is all about velocity/burn rates, not top accuracy.
Lastly there is zero relationship driven by speed in a match barrel…..lit’s all about individual lots.
All of this established fact in the performance driven RFBR world where plenty of ratchets live.

Lastly ELEY can be quite good but past 100 the flat nose hurts….R50, SK, Lapua will outperform, especially Lapua.

joelpend wrote yesterday at 10:38am:


joelpend,

I share your concern & had done some research on the subject.  The range I shoot at is approximately 203ft. above sea level.  At that elevation, ignoring temperature, the transonic range is roughly 900 to 1340fps; the muzzle velocity range of just about all the match-grade ammo.

BTW, I've tried several brands of ammo with rated velocities of 1070 to 1120fps (actual velocities of 1039 to 1148fps).  In all cases the rifle's precision at 200yds is best at the higher velocities.  The absolute best precision was with RWS100 at a measured velocity of 1141fps, but I'm not willing to spend around $40/box for RWS100 assuming it's available.

Wayne

I could be wrong but I slug each end and measure. Couldn’t tell any difference. I know that’s not the best method. Next time I’m where I used to work, I will take my rifle in and check it in the cal. lab with the .0002 pin gauges. My pin gauge set only goes .0005.


Tom Klinger

TomKlinger wrote yesterday at 1:09pm: