This week tested various ammo in my Marlin Model 60 semiauto (19-inch barrel, 3x-9x scope at 7x) and Rogue Chipmunk single shot bolt action (16-inch barrel, iron sights) .22 rifles. Outdoor range, 25 yards, temp 90 degrees, little wind, bench rest.
Both rifles have 1:16 rifling, right-twist in Marlin and button in Chipmunk.
Decided to stick with American ammo, .22 LR, copper plated, hollow point or solid nose, mostly high velocity but two hyper velocity, four brands in seven versions, five shots each at 2-inch bull's-eyes (1-inch 10 ring).
The Marlin Model 60 did fine with all ammo, shooting diameters of 1/2-inch to 1 3/4 inches. The Chipmunk did well with all the HV but lousy with the two hyper velocities, shooting them high and to the right.
The wider diameters usually were caused by one shell a bit farther away than the other four. Could have been flyers but probably just my aim.
Both rifles did best with Remington ammo, either HV HP CP 36-gr or HV SP CP 40-gr. Big surprise was Marlin shooting Remington Yellow Jacket (HP CP 33-gr) as accurately as high velocities.
The Chipmunk actually did best with Winchester Super-X HV SP CP 40-grain, but I disqualified it because three of the five shells were difficult to extract. No misfires with any of the ammo in either gun.
Other ammo tested was Federal Classic HV HP CP 38-gr, CCI Mini-Mag HV HP CP 36-gr, and CCI Stinger Hyper Velocity HP CP 32-gr.
The Marlin 60 put 33 of 35 shots into the 2-inch bull's-eye, but the Chipmunk did only 16 of 35.
Best was the Marlin 60 putting all five shots of Remington HV HP 36-gr into the X within a half inch.
Worst was the Chipmunk putting all five CCI Stinger Hyper Velocities 2 1/4-inches high and to the right.
The test was fun and enlightening. Remington is now my choice for these two guns instead of CCI Mini-Mag. Eventually I'll do this kind of ammo test for all my guns.
Biggest lesson? Confirming that matching the ammo to the gun can make me twice as accurate or twice as inaccurate. Never quite believed that until validating it with my own gear.