by B.B. Pelletier
Crosman’s Mark I Target is a beautiful single-shot air pistol. It resembles the Ruger Mark I.
Well, today I’ll test the velocity of my Crosman Mark I pistol. And you’ll recall that I’d planned to adjust the gun’s power for you as well. Well, I discovered that the pistol was already set as high as the adjustment will go, so that’s where I’ll start this report.
This buggered-up screw sticks out the front of the receiver, just beneath the barrel. Turn it out to slow the pellets and in to speed them up.
The gun has two power levels that are determined during cocking. The first click of the twin cocking knob selects low power and the second click is for high. On low power, the trigger is single-stage, and on high power it’s two-stage. It didn’t have as much creep on low power as I remembered, but there’s definitely a little bit.
On high power, I’ve adjusted the trigger to release at a much heavier weight than I remembered, but I do remember that I had backed it off to release at less than a pound and it had become unsafe. So, I cranked in a bunch of trigger adjustments, and now it breaks at around 5 lbs.
Adjusting the trigger is a matter of turning in or out on the Allen trigger-adjustment screw located in front of the trigger blade. You can make the second stage break very light, but just remember to test it with an unloaded gun, because you don’t want a gun that fires on its own.
The trigger adjustment screw is on all Mark I and II models.
As it turned out, my pistol was set to the highest power level it could attain, so the first velocity figures are the best it can do. Since it’s a Crosman gun, I reckoned it would be best to test it with Crosman Premier pellets first.
The .22 caliber 14.3-grain Crosman Premier pellet averages 431 f.p.s. from my Mark I on high power. The spread went from a low of 428 to a high of 434 f.p.s. The average muzzle energy is 5.9 foot-pounds at that velocity.
On low power, the same pellet averaged 310 f.p.s. with a spread that was somewhat larger. It went from a low of 305 to a high of 316 f.p.s. The average muzzle energy is 3.05 foot-pounds.
Then, I adjusted the power as low as it would go. The power-adjusting screw turned counter-clockwise until it seemed to stop, which I guess is a design feature. At that setting on high power, the pistol averaged 325 f.p.s. with a spread from 320 to 331 f.p.s. That’s a muzzle energy of 3.35 foot-pounds.
On low power, the velocity averaged 132 f.p.s. and ranged from a low of 127 to a high of 141 f.p.s. The muzzle energy averaged 0.55 foot-pounds.
I don’t know what benefit the power adjuster gives, since high and low power can be selected during cocking. I can understand why Crosman eliminated this feature in the later years of the pistol’s production. Maybe, with a modified gun there’s an advantage, but with a stock pistol I don’t see the need for power adjustment.
Is it repeatable?
Once the low-power adjustment test was finished, I adjusted the screw all the way back to high power and shot it once more through the chronograph. It registered 437 f.p.s., so close enough to where it was before.
Velocity with Hobbys
RWS Hobby pellets weigh 11.9 grains in .22 caliber, so you know they’re going to go faster than Premiers. On high power, they averaged 472 f.p.s.. The spread went from 464 to 479 f.p.s. The average muzzle energy was 5.89 foot-pounds.
On low power, they averaged 355 f.p.s., with a spread from 352 to 362 f.p.s.. The average muzzle energy was 3.33 foot-pounds. Do you notice how close the power is to the results I got with the Premier pellets?
Velocity with Gamo Hunters
The Gamo Hunter pellet weighs 15.3 grains in .22 caliber. On high power, they averaged 413 f.p.s., with a spread from 408 to 416 f.p.s. That works out to an average muzzle energy of 5.8 foot-pounds, or just a little behind the other two pellets.
On low power, the average velocity was 306 f.p.s. The spread went from 304 to 310 f.p.s. The average muzzle energy was 3.18 foot-pounds.
So, my Mark I is pretty consistent in the velocity department, as we expect a good CO2 gun to be. All shots were indoors with an average temperature of 70 deg. F.
The hold is near-perfect, improved over the stock Ruger Mark I grip by the super-ergonomic grips Crosman designed. And, the gun seems to get plenty of shots per CO2 cartridge. Let’s see what it can do downrange next!