The 10/22 Air Rifle Kit Part 2
Scoped and ready for the 10-meter range
By Dennis Adler
Pellet rifles fall into a number of categories from Olympic competition to small game hunting and just plain old plinking and target shooting. The best pellet rifles are usually expensive (or comparatively expensive) precharged pneumatics (PCP), premium underlever spring air rifles, like the RWS Diana 460 Magnum, spring piston break barrels, like the Beeman R7 Elite Series, while at the lower end of the price spectrum are CO2 powered air rifles using an 88 gr. CO2 cartridge or dual 12 gr. CO2 cartridges. The Ruger 10/22 falls into the last category and with its sealed air chamber in the buttstock has enough power to send 4.5mm pellets downrange at velocities capable of being effective for small varmint hunting and practical target shooting, both of which are greatly enhanced with the use of a variable power scope like the Mantis. Pyramyd Air has picked a good match for the Ruger 10/22 in the Rifle Kit.
Recapping the 10/22
Using the same internal design as the Umarex Cowboy Lever Action model means you have two 12 gr. cartridges supplying CO2 to the rifle. Umarex recommends a drop of RWS Chamber Lube on the tip of each cartridge as it is inserted as well as the O-ring on the piercing screw, which I recommend with this rifle; a good seal is everything with this system. Once you turn down the piercing screw, the forward facing CO2 is pierced by a pin in the front of the chamber and the rear facing cartridge is pierced by the seating screw that shrouds the front of the second cartridge. When the seating screw is turned down until it stops, all of the air from both cartridges is released inside the chamber, which is sealed by the large green O-ring on the seating screw. This gives the gun a factory-rated velocity of up to 700 fps. When I did my initial test of the pre-production sample, the Ruger 10/22 was to be rated at 650 fps. So now with a production gun I am going to recap the CO2 loading and then run a chronograph test with the same Meisterkugeln 7.0 gr. lead wadcutters I used with the Umarex sample gun. I am also going to run a test with premium grade RWS R10 Match wadcutters and lightweight Sig Sauer Match Ballistic alloy wadcutters to see what the maximum velocity can average. This is probably where we will see the 700 fps speeds. With the sample gun, alloy wadcutters were clocking around 718 fps.
The 10/22 is a very familiar style of small caliber carbine, as so many semi-auto rimfire and centerfire rifles have been based on William B. Ruger Sr.’s classic 10/22 design from the 1960s. At the heart of the gun is the rotary magazine, which was quite a big deal when it was introduced. It was featured in most of Ruger’s early magazine advertisements. The CO2 model uses on the general magazine design but adds the 10-round rotary pellet magazine at the front. It loads into the receiver the same way as the rimfire mag. The sights are the same, too, and with the rifled barrel, the sample gun had delivered fairly tight groups at 10 meters shooting from a benchrest. With Meisterkugeln, my best 5-shot group from 10 meters measured 0.437 inches in the 9, 10 and X rings with an average velocity of 630 fps. I had also shot the RWS R10 Match and scored a best five rounds at 0.53 inches in the 9, 10 and X rings, with four of five hits overlapping. My expectations for the 10/22 with the Mantis scope at 10 meters, then, are very high!
New velocity checks
With this new production gun in hand I loaded the two CO2 cartridges and ran my first velocity test with the Meisterkugeln. Average velocity for 10 shots with 7.0 gr. lead wadcutters was 644 fps with a high of 657 fps and a low of 635 fps. The R10 matched closely at an average of 642 fps and the alloy wadcutters broke the 700 fps line with an average of 708 fps, a high of 722 fps and a low of 699 fps.
For today’s accuracy test, I will be sighting in the scope at 10 meters and shooting from a rest, as well as running a 10 meter test outdoors firing from the shoulder. With the scope mounted and the vertical and horizontal alignment of the crosshairs verified both from the shoulder and benchrest by lining them up on a target and making sure the rifle is perfectly vertical. I had to make one slight adjustment of the scope in the mounts, loosening the screws and rotating the scope about 3 degrees right, to get it perfectly centered. I was ready to sight the scope in for the bench test at 10 meters. I found the best combination was setting the objective to 20 yards, and for my preferences, the power zoom at the rear to 6 (it adjusts from 3X to 9X), and then adjusting the focus ring for my vision. At 10 meters both the reticle and target were sharp. It took a total of 8 shots to get the scope zeroed in on the bullseye, shooting from the rest and cocking the action for each shot.
Firing from the rest at 10 meters I put 10 shots into the bullseye and 10, all overlapping, with a total spread of 0.5 inches. That would put any five shots inside that spread at 0.25 inches. Scoped and rested, I think that is about as good as I can do. The proof will be in my 10 meter shots fired standing and firing from the shoulder.
That proved a bit more challenging with a slight crosswind and lacking the support of the benchrest. I took a long time to shoot my 10 rounds and again, rather than working the double action trigger, I used the charging handle to cock the action for each shot. The single action trigger pull on this gun was a very light 2.0 pounds, with just a fraction of an inch of take up.
The design of the gun, as I see it, is such that for a blowback action to work and re-cock the action after each shot using the rotary (pellet) magazine, like the rimfire model, would require a more complex (i.e. more expensive) design, and maybe even cost some of the Ruger’s 650 fps average velocity in the bargain. For carefully aimed shots, working the charging handle to cock the action is no more laborious than shooting with a bolt action rifle. My best 10-round target had a spread of 1.1 inches with a best five shots at 0.5 inches, but all hitting left of center and clipping the 8 ring. Fired semi-auto with the double action trigger, which has a pretty heavy pull, accuracy is going to suffer without question, but for my money, shooting with the Mantis scope isn’t about speed, it is about accuracy and the Umarex Ruger 10/22 will give you that with or without optics.
In Part 3, I will wrap things up (weather permitting) shooting from the bench at 25 yards to see just what this pellet rifle is really capable of.