Weird .22 Pellet Stability Behavior

[Mink]

Lately I’ve been working on tuning my new Taipan Veteran Long .22 for ~long range shooting (100-150 yards). However, I’ve run into some unexpected behavior regarding pellet stability at range. Note that the gun is tuned to shoot JSB 18.1s at 880 fps. 

• Inside 40 yards: Very accurate, one ragged hole most times. 
  
• 50 yards: Average 3/4”-1” groups with the occasional 1/2”. Also, I occasionally get a fliers 2 MOA or so off. 
  
• 75-100 yards: Accuracy not impressive. At 100 yards, I’m getting 3-4” groups with no wind and much worse with a breeze. Seems 1/2 of shots stack close, but the other half are unpredictable fliers. 

I recently took some shots at 100 yards and filmed to the best of my ability in 240 fps on my iphone. Sure enough, footage revealed pellet spiraling at longer ranges. I checked for moderator clipping and found no damage of any baffles, and I achieved comparable accuracy when I took the moderator off. 


On a whim I decided to try some Air Arms 16gr field diabolos I had laying around, as they have head diameter of 5.51mm compared to JSB 5.52mm. I can feel the difference in pressure needed to close the bolt when seating the pellet. Same tune chrony’d at 940 fps. Interestingly, the 16gr pellets held ~2-2.5” groups at 100 yards, with not nearly as many fliers, and requiring 2 MOA less holdover. However, when I shot them at 50 yards the groups were less impressive than the 18.1s, probably 1-1.25” average. 

I was wondering if anyone had any similar experiences to this with their Veterans or similar LW/CZ barrels? I guess I am surprised because I always hear the 18.1s being touted as the far superior pellet at range due to higher BC, and I even hear that the barrels on these guns are designed to shoot the 18.1s. But I guess in some barrels the 18.1s are too wide and are unstable past 50 yards? 


Also, because most everybody associates .22 with 18.1gr JSB, I was wondering if the same velocity range of 860-900 fps is usually optimal for the lighter 16gr pellets, or if they do better generally with more speed?

 

[Yo]

I would try AA 18gr and a different lot number tin of those JSB 18gr and try again. Don't know lot number? Buy from different vendor like Trenier.

 

[jwrabbit123]

Hi I have a veteran std in 22 mine haas a original cz barrel , it is one with out the emblem on stock , I put a 24 inch slug barrel on it from airgun havn and it shoots flawless pellets with either barrel out past 150 yds and under 1 moa at 100 ,

I had had same issue as your gun with other guns and I found looking with a bore scope you will have defects in barrel and a bad crown , Or a extremely dirty barrel ,

I would start with a good cleaning if this doesnt fix it start polishing barrel and recrown it

LOU

 

[davecole]

I probably tried just about every reasonable brand and weight of pellet out there in my Vet.

The JSB 15.89 were the best that I found. Tried the AA's as well. flyers. too many for my liking. IMHO the AA's are JSB rejects anyway.. That's why they're cheaper.... 

 

[Jayson]

AA are not rejects, not by along way! They are just not paying PI to distribute them and they have their own die in the same factory= better in my book! My advise would be to call Georgia Airguns and talk to Charlie, he knows those barrels inside and out and will recommend AA pellets in those barrels lots of times, especially in 25 cal. Good luck.

 

[Mink]

@davecole @Jayson The primary reason that I chose the AA over JSB 16gr is because the advertised head diameters are different. AA=5.51mm JSB=5.52mm. Maybe they are identical in reality but my idea was to try a pellet with a smaller head diameter. Also from my observations the skirts on the AA pellets actually appear to have fewer deformations than the JSBs I have used. But then again that may come down to lot #, etc. 

In any case, @davecole what speeds do you find work best in your Vet with the JSB 15.89s?

 

[davecole]

@Mink

Typically, I’ve found JSB 15.89 like speeds 875-920ish in my guns. My Vet shot them at 895 with very suitable accuracy. 

 

[Xbowsniper]

Mink,

I've been investigating issues like this for a while, and a while back, a couple of guys that used to frequent my home range here on Long Island, created some slow motion footage. It explained everything that I had suspected, stability wise.

Here is that video:

https://youtu.be/C7c9Noa4v4g

Now, this was shot out of a highly tuned Benjamin Marauder, .22. What do you notice?

If you picked it up, it is one of the telltale signs of too much speed.

The twist of the barrel, thus the spin of the pellet, is clockwise (right hand twist).

If one looks carefully, the pellet is spiraling counterclockwise, the opposite of the spin of the pellet. This is a telltale sign of too much speed. In this particular case, they only had to lower the velocity around 25 FPS in order to prevent the spiraling that was visible in the video. Your individual results may be different.

This is one of the reasons why I compete and shoot almost exclusively at 12 ft.lb......speed kills.....

Tom Holland 

Field Target Tech 

 

[JungleShooter]

Super interesting! ➔ Yes, I sometimes feel that my LW barrel (Skyhawk .22) does not perform like it should, either — at least compared to most of the posted paper targets on the forums. Not at 50y, not at 100y....

Of course, I take full responsibility for any shooter errors — and I still have a lot to learn....





About pellet diameters:

If you purchase your JSB pellets directly from Predator International, they will sell you the 15.89gr pellets with a specific head diameter — unlike the other pellet peddlers out there that chose to rob you of that choice.

▪The 15.89gr JSB is available in: 5.50, 5.51, 5.52, 5.53

▪The 15.89gr AA is available in: 5.51, 5.52



Have you checked H&N pellets? They have two with varying head sizes:

▪H&N Field Target Trophy (14.66gr): 5.53, 5,54, 5,55

▪H&N Baracuda Match (21.13gr): 5.51, 5.52, 5.53





Matthias