Spring gun tuning: Part 1
Spring gun tuning: Part 2 – Building a mainspring compressor
Spring gun tuning: Part 3 – Mainspring compressor continued
Spring gun tuning: Part 4 – Let’s disassemble a gun!
Spring gun tuning: Part 5 – Powerplant disassembly
Spring gun tuning: Part 6 – Disassembly completed
Spring gun tuning: Part 7 – Disassembly of other spring guns
Spring gun tuning: Part 8 – Disassembly of other spring guns, continued
Spring gun tuning: Part 9 – Cleaning and deburring
Spring gun tuning: Part 10 – Lubrication and reassembly
Spring gun tuning: Part 11 – Lubrication and reassembly continued
Spring gun tuning: Part 12 – Finish reassembly and test the gun
by B.B. Pelletier
Well, it’s time to range-test the results of our Beeman R1 tuneup. You may recall that I said I wanted to lower the power to have a light-cocking, smooth-shooting rifle. What I didn’t tell you was that my R1 had a gas spring in it before the tuneup. It was working fine, but I was tired of having to cock 50 lbs. every time I wanted to shoot. I had a special low-powered mainspring that I used with the factory piston and spring guide. After the tuneup, I knew the gun was easy to cock and shooting smoothly, but I had to take it to the range to learn the rest.
My R1 has a plain walnut stock, a Vortec muzzlebrake and a Bushnell Trophy 6-18x in Leapers Accushot medium rings. The low-power tune makes it very enjoyable.
I hadn’t counted on this benefit, but the R1 is now extremely quiet. I doubt my neighbors would know I was shooting if they didn’t see the gun or hear the strike of the pellet. After testing magnum guns for the past 6 months, it was a real pleasure to shoot a rifle this smooth and quiet; sort of the reason I got into airgunning in the first place.
Low power – but not THAT low
The tuned R1 spits out a 15.8-grain JSB Exact at 645 f.p.s., on average. That works out to 14.67 foot-pounds at the muzzle. A factory R1 in .22 caliber will generate about 17-19 foot-pounds, so this tune is definitely lower, but not so much that I can’t do the same things with the rifle. And, that was also tested at the range.
Shooting an R1 requires a lot of technique. You simply cannot grab the stock and hope to hit anything. But, let it float and watch out! My results with JSBs at 40 yards were not as good as I had hoped. Usually, the JSB Exact groups tighter than any other pellet, but not in my R1. The best I could do was still slightly over an inch.
Beeman Kodiaks, however, brightened the day. They sailed through group after group and nothing measured larger than one inch. The best for the day was 0.847″. It looks like only four holes, but two pellets went through one of them.
Having also had some luck with heavy Logun Penetrators in the past, I tried them, as well. The best group of five measured over 1.3″. That left Kodiaks as the pellet of choice.
One of these holes passed two pellets. This was the best group of Beeman Kodiaks.
The barrel joint loosened during the shooting, so it would not stay in any position other than closed once the gun was cocked. I expected this to happen because of the lubrication. It didn’t affect accuracy, but I still tightened it once I returned home. Remember, the test for the pivot bolt being tight enough is that the barrel of a cocked gun will stay where it’s put.
This rifle is now a genuine pleasure to shoot. I am inclined to just sight it in at 20 yards and leave it that way. It might even become a “go-to” rifle, because it is just as quiet as my TX200 or Talon SS and lots of fun to shoot.