Career Infinity by Shin Sung – Part 4
by B.B. Pelletier
This is our last look at the Career Infinity. You may recall that the inlet valve seal had failed, and I replaced it in one of the reports. Then the replacement valve failed and I replaced it with a special Teflon inlet valve made by Boris at Pyramyd Air. I said in part three that I would let you know how well the new seal is holding.
Boris made the Teflon inlet valve seal on the left to replace the three-part inlet seal assembly that came with the Infinity. Less mass may keep the seal from deforming too much.
Well, it has held air for two months now, plus the gun has been refilled a number of times. I’m ready to pronounce the gun fixed. Boris’ design works fine. On to the accuracy test.
I shot the rifle for accuracy last Friday in winds that varied from 5 to 20 mph. The wind speed increased as the shooting progressed, and even a Condor I also tested was hard-pressed to shoot under one inch at 30 yards. The Infinity did much better than that, as you’ll see.
Air Arms domes
Air Arms domes that Pyramyd Air used to carry are made by JSB, so they should be pretty much the same thing, but they’re not. They vary in small ways, which makes their performance vary, as well. Usually, I get better performance from a JSB, but with the Infinity, that wasn’t true. The Air Arms dome that I used to get the rifle sighted-in proved to be the most accurate lightweight pellet tested.
Other groups with the same pellet were similar, but not quite as tight. At this point, I noticed a 5″ water hose laying just beyond where I was shooting, so I repositioned the target box so the pellets would be stopped by a tree. No sense in ruining an expensive item like that! The new location gave me only 30 yards distance.
JSB Exact domes
Next, I tried JSB Exact domes, but the results weren’t worth showing. The groups were all an inch or larger, and with the Air Arms groups in the bag I didn’t need them.
Remember–I was shooting in a strong wind. The rifle was set to the lowest power setting, because the Eun Jins responded so well. I shot groups at higher power, but they produced the same results at the same aimpoint at 30 yards. So, I didn’t see any value in shooting at that setting. On the lowest setting the velocity was somewhere in the low- to mid-700s, giving me a power of about 32.5 foot-pounds. I can get about 30 shots at that power setting if I work the power wheel.
Adjusting the power wheel to keep velocity consistant
PAY ATTENTION, because I’m about to explain how adjusting the power wheel keeps you on the power curve. As I passed shot No. 10, I adjusted the power wheel up one notch to keep the velocity the same. After that, I adjusted up one notch with every new cylinder of six. I didn’t bother chronographing each shot, but the rifle continued to shoot to the same point of aim at 30 yards, which is a good indication it’s shooting the same. That is what the Koreans told Rocket Jane Hansen to do, and it’s how to use the power wheel to get a large number of shots at a similar velocity.
Obviously, this cannot be done when shooting at the highest setting, because there is no place to go. You are already at the highest power. But If you back off the power, as I did, you can keep bumping it up and extend the number of shots AT THAT POWER LEVEL.
This is self-evident to anyone who shoots one of these Korean rifles. I did it with my Career 707, without being shown, back in the mid-’90s. You are simply allowing slightly more air to flow as you adjust up. After shooting the first 100 shots, it would be remarkable if this DIDN’T occur to you!
This is the end of this report. My take on the Infinity is that it’s a powerful, accurate smallbore air rifle. It likes the Eun Jin pellet so well that it’s a waste of time shooting anything else. Stock up on Eun Jin domes and don’t waste your time with anything else.
The inlet valve is a potential weak spot, but it’s fixable. Boris at Pyramyd Air knows what to do to fix the valve and his fix works. If you want a powerful hunting rifle, the Career Infinity is a good value at a reasonable price.