Career Infinity by Shin Sung – Part 4

by B.B. Pelletier

Part 1
Part 2
Part 3

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.


Five shots from the Infinity at 35 yards with Air Arms domed pellets landed in this group that measures 0.651″ c-t-c. Notice that the holes are slightly elongated, indicating a slight instability.

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.

I hadn’t brought Beeman Kodiaks along this time, but they would be worth a try. However, I believe I found the best pellet in the 28.4-grain Eun Jin.


This group of five Eun Jins at 30 yards demonstrates the superiority of this pellet. It measures 0.547″ c-t-c. And this is only a representative group!


This was the best group of five Eun Jins at 30 yards. It measures 0.443″ c-t-c. I took the time to zero the scope for this, because the Eun Jin is clearly the pellet to use in this rifle.

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.

32 thoughts on “Career Infinity by Shin Sung – Part 4





  1. Mr. B.,

    No, it wouldn’t. The AirForce power wheel is far less descrete than these Korean guns. It may not do much for a large change, then all of a sudden it jumps a lot.

    You need a chronograph when adjusting an AirForce power wheel.

    B.B.


  2. OT…I cannot believe what a difference an inconsequential adjustment (I thought) could make.
    I’ve been having a real trying time with my Gamo compact. Two inch groups were normal with the odd flyer…sometime off target.
    Over the weekend I re-read B.B.’s 7 part pistol shooting series and noticed the emphasis on the adjustment of the width of the gap in the rear sight (the Gamo has an adjustable width).
    I had left mine at the factory setting, which was a sliver of light on either side of the front blade, viewed through the rear sight.
    So I opened her up as B.B. suggests so thier was a gap on either side of the front blade, nearly the width of the blade itself.
    Amazingly the front sight seemed to sit exactly where I place it instead of dancing around as it had done before.
    And my groups are now centered around the 10 in a .75″ group (5 shots).
    Again…amazing how much difference one little adjustment made.
    I know this stuff is probably common knowledge to any competition shooter…but to those of us who don’t have access to such events (none where I live) B.B. and this blog are a godsend.
    CowBoyStar Dad


  3. B.B.

    Interesting…

    If folks want 32.5 foot pounds from that gun, I’d be surprised.. most folks are looking for more like 40 foot lbs.. or the 53 that the PA site promotes..

    It’s to bad it was so windy.. I wonder what would happen at 50 yards and 3/4 power setting moving up to full power as you shoot down the tank..
    On the AR-6, I saw the Eun jin pellets sideways at 50 yards when over 750fps.. and my accuracy fell way off.. I wonder if the infinity can hold those groups on a higher power.. I’d bet not.. those Eun Jins will start to tumble over 800fps..

    Just a Wacky Waynes’ two cents..


  4. Glad to see the teflon inlet valve works well at those pressures! I’ve used teflon for Benji and Sheridan inlet valves lately but didn’t have an idea of how well they would hold up, this seems to confirm that its a good material.


  5. B.B.

    Can we assume that all copies of a particular rifle will like the same brand of pellet or could there by variation between different copies? I read that the reason why individual rifles like different pellets is because of subtle differences in tolerances.

    Matt61


  6. Wos.,

    The purpose of this site is to encourage the sharing of information that is airgun related. My take on your last two posts that I read are that they are discouraging and disparate to this end.

    Sarcasm from a know-it-all is unnecessary.

    Please feel free to contribute something worthwhile from your apparent vast experience.

    kevin


  7. Aloha B.B.,

    Thanks for a great evaluation. Would it be better to use a chrony & find the rifles power curve & optimum fill pressure then start from there? Didin't you mention in part 2 that you thought the gun needed a much higher fill than 3000 psi. Did you ever find the best fill pressure? If I start on the low setting & turn the power wheel up 1 click after every magazine I'm still left with 6 more clicks on the power wheel. Shouldn't you have started @ 5 or 6 clicks below full power? Did you get to test any other heavy pellets or air bullets that are available from Daystate or Eley? Thanks again.
    Aloha
    Scott


  8. Matt,

    It’s never good to assume all rifles will like the same pellets. There does seem to be a tendency among the same model, but as you mention, subtle variations can make a difference.

    B.B.


  9. Scott,

    I only tested the pellet I mentioned in the report.

    Why start near the top of the power band? You don’t need all that power for 90 percent of the game animals you will hunt, so why not use a more reasonable 32 foot-pounds and get triple the shots?

    I never did ascertain the power curve because my fill hose was leaking. I didn’t want to blow the connections, so I stopped at 3,000 psi. But the top is higher than that.

    B.B.


  10. On rear sight width:
    There is no absolute. Width depends on lighting conditions, shooter’s eyes and shooter’s skill. With enough light and sharp eyesight, a narrow gap gives more precision. Some shooters match their rear sight to each venue they shoot at.
    When I shoot my Steyr LP10 at formal matches where the target is nice and bright, i prefer a narrow gap. At home the same gap is too tight for me.


  11. B.B.

    But how much of that 32 fpe at the muzzle will be retained @ say 80 yrds? At that distance I'm going to need more fps @ the muzzle to get more initial fpe. If I shoot a heavy pellet at 900-950 fps my range increases if the pellet is accurate & has a good BC. If I need 30 shots in one hunting session I need to go back to the range.

    Aloha
    Scott


  12. Scott,

    First things first.

    First you need to be able to hit things at 80 yards. Can you do that? By things, I mean one-inch targets. Repeatedly.

    Don’t sweat the ballistics until you’re sure you can get a pellet to the target.

    B.B.


  13. B.B.

    I can hit a 3" target @ 100 yrds 9/10 consistently. I just started shooting air rifles a little over a year ago & shoot up to 5 times a week every week.

    Scott


  14. Scott,

    That’s good, but 3 inches isn’t an airgun kill zone. That’s a deer-hunter zone.

    You need to back up to the point at which you can hit a one-inch circle that many times. Then you have the right to be concerned about the ballistics at that distance.

    If you are doing that well at 100 I’ll guess you can shoot one inch at 60 yards.

    B.B.


  15. Thanks B.B.

    I will have to practice more to get it down to 1″ @ up to 75 yrds. Of course those 100 yrd shots were done from a bench with no wind, etc, etc….. If I can get it down to 1″ @ 75 yrds how much fpe would I need to have @ the POI?

    Scott



  16. Henry,
    TF97 showed up Friday. I was not able to open it until today.

    Stock is cracked a little. Reports on the TF97 indicate cracking at the screws is common… due to over tightening. The crack is very minor.

    Was able to mount a scope and fire a dozen shots before my fingers froze. Couldn’t get good groups… but I was real cold and rushed. Will try again another day.

    DB


  17. BB,

    I rarely shoot a squirrel at less than 125 yards, and they’re all head shots, about half of them with the squirrel leaping from one tree to the other in the thick woods, so that even if the shot doesn’t finish him off, the drop onto a branch or the ground will. If I decide to resume squirrel hunting someday, that’s the kind of story I’d like to publish online, anyway:).

    Unfortunately, in my woods, its rare to see an entire deer clearly at 100 yards, much less a squirrel’s head. I think 32fpe would be sufficient, also:).



  18. twotalon,
    There’s a bunch of beavers that are kind of wrecking a stream near here. I need to get rid of them, and the only clear shot I have is about 100 yards.

    Scott


  19. Aloha Twotalon,

    We have Mongoose here in Hawaii that are very hard to get close to. As well as wild turkey & feral cats. The cats & mongoose are a big problem here. They are destroying many of the indigenous birds.

    Aloha
    Scott


  20. B.B.
    Thanks for the great report – saves me plenty of time and money.

    For the group, I can attest to this:
    If you are nice, Boris will send you one of his inlet-valve gizmos for free.
    I pump my Infinity up to just over 3100PSI, and the first 18 shots all stay above 850FPS, starting at low power and dialing up one notch per cylinder. I’m in the 40FP energy range – more than enough for small game.
    I can’t get 30 shots like B.B. can, but,I think I might have a slightly stronger hammer spring, given that I seem to get higher velocities.

    I’ve had good luck with the Eun Jins. I’m not as skilled as B.B., but at 30 yards I can get close, and have done some 1.5″ groups out to 45 yards. That range is about my practical skill limit.

    It is good to hear the comment on the EunJins. I have this awful temptation to buy an assortment and start testing, but it seems this gun and this pellet are a fairly matched set, and lead is getting expensive.


  21. Scott,

    I’ve been a hunter all my life. Please don’t interpret what I’m going to say as coming from a tree hugger that only eats sprouts (apologies to .22 multi shot).

    I think (depending on pellet selection for max ft lbs) you have enough gun for feral cats and mongoose at the range you can shoot 1″ groups consistently. Unless you can get within 10 yards of a grown beaver please don’t shoot it with a career infinity.

    I belong to a trout club with many lakes interconnected with streams. We have an ongoing problem with beavers. I’m very familiar with what it takes to humanely remove these tough pests. The overwhelming odds are that you will only wound a beaver with a pellet gun. You need more than a pellet gun, please. Please also be aware of hunting seasons for beaver and whether you are even allowed to take your beaver during the hunting season. In Colorado, since beaver create wetlands, in some areas you’re not allowed to remove the beaver even during season because the wetlands are protected. Know your regulations.

    This isn’t meant to be preachy. I just don’t want your gun confiscated along with a ticket being issued for a heavy fine and possible summons.

    kevin


  22. Ed,

    If you want to try just one more pellet in your infinity, try the kodiak.. I found they can take the most feet per second without tumbling.. and so give the best accuracy and foot lbs at long distance..

    Wayne,
    Ashland Air Rifle Range


  23. Kevin,

    I think there are 2 scotts replying to you as there are no Beavers in Hawaii & I didn't make that post.

    Aloha
    Scott in Hawaii


  24. Scott with the beaver problem,

    I’ve been a hunter all my life. Please don’t interpret what I’m going to say as coming from a tree hugger that only eats sprouts (apologies to .22 multi shot).

    Unless you can get within 10 yards of a grown beaver please don’t shoot it with a career infinity.

    I belong to a trout club with many lakes interconnected with streams. We have an ongoing problem with beavers. I’m very familiar with what it takes to humanely remove these tough pests. The overwhelming odds are that you will only wound a beaver with a pellet gun. You need more than a pellet gun, please. Please also be aware of hunting seasons for beaver and whether you are even allowed to take your beaver during the hunting season. In Colorado, since beaver create wetlands, in some areas you’re not allowed to remove the beaver even during season because the wetlands are protected. Know your regulations.

    This isn’t meant to be preachy. I just don’t want your gun confiscated along with a ticket being issued for a heavy fine and possible summons.

    kevin




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