I’ve got 2 different JSB 25 grains. You can tell by the skirt width that they changed it…but why? I believe the one on the right is the newer design.
Why did JSB do this?
- Thread starter Maizen
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old on the left and redesigned on the right i think, i only have the new fx version and never tried the old ones.
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Even for pellets having no MKI / MKII distinction, JSB frequently changes little things when they make new dies. They don't seem to mess with the head geometry too much but differences in skirt thickness and depth wax and wane over time. I've seen it with almost every pellet in the .177, .22, and .25 lineups.
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I've seen this with the 18.13s, and the thicker skirts shot like hot garbage while the thinner ones were sub moa in my back yard out of my mutant.
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I have seen sort of the same, first time was in a tin of H&N barracudas, and i saw it again yesterday trying some Rifle thunders in my Vulcan 3.
But in my case it is within 1 tin, and when i see i think " damn their tool broke" even if it is extremely few i find with this skirt deficiency
But in my case it is within 1 tin, and when i see i think " damn their tool broke" even if it is extremely few i find with this skirt deficiency
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old on the left and redesigned on the right i think, i only have the new fx version and never tried the old ones.
the fx "redisigns" i just got (on the right) have a deep cup with thin walls.
i believe this thinner profile helps expand more easily to conform to the rifling. or that's the idea...
monsters (fx) - jumbos (jsb) - barracuda (hn)
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I believe it's because the center of gravity is further forward which should make it more stable.
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I believe it's because the center of gravity is further forward which should make it more stable.
All going to depebd on your rifle, barrel, velocity, etc...Some rifles may like the other ones better....when you find a lot that works well buy a bunch!!
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Shallow is opposite of deep, so the shallow ones are on the right side.
just going by what DOUGER said. I have no experiences in comparing the two.
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Ok this is what I was thinking after the fact but I think at the moment I thought he was referring to skirt width. Thanks
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@BigRagu This is new information to me that I read on another forum. The labels are to be read from right to left. The final two numbers (first two numbers on the left) should represent the die numbers on the sticker. What I took from the post was that if I have good batches, to pay attention and compare the contents of tins with matching die numbers. Conversely, I think it would be prudent to do the same with bad batches. This seems to align with doing a similar thing in business when purchasing bulk products/raw materials that are produced with a reasonable amount of varying consistency. The source of the information I provided (as I understand it) is in the following link: https://www.airgunforum.co.uk/community/index.php?threads/a-guide-to-jsb-pellet-tin-label-meanings-and-what-to-look-for.218132/
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I've have first hand experience with both these pellets.
Initially, I tuned my .22 Impact M3 with the JSB 18.13gr shallow pellets. It was really accurate out to 90 yards. I was getting an average group size of 3/4 of an inch with a 5 shot group. Flyers was very minimal.
I went ahead and bought several thousands of the JSB 18.13gr, and I didn't notice it at first, but I ended up with the deeper cup pellets. Now my M3 shoots like crap, and I will have to wait to retune my gun to the .22 JSB 25.39gr.
It's unfortunate that I spent many different days and hours getting my M3 to shoot great, just to recieve a run of different pellets, and have to start from scratch again with my M3.
On the bright side, my Mrod and Prod sure loves these JSB 18.13gr deeper cup pellet.
Initially, I tuned my .22 Impact M3 with the JSB 18.13gr shallow pellets. It was really accurate out to 90 yards. I was getting an average group size of 3/4 of an inch with a 5 shot group. Flyers was very minimal.
I went ahead and bought several thousands of the JSB 18.13gr, and I didn't notice it at first, but I ended up with the deeper cup pellets. Now my M3 shoots like crap, and I will have to wait to retune my gun to the .22 JSB 25.39gr.
It's unfortunate that I spent many different days and hours getting my M3 to shoot great, just to recieve a run of different pellets, and have to start from scratch again with my M3.
On the bright side, my Mrod and Prod sure loves these JSB 18.13gr deeper cup pellet.
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I was going to start a new post but thought I would just add to this one. My .177 Marauder suddenly started to exhibit some unusual inaccuracy. I spent time inspecting and eventually decided on complete tear down for preventative maintenance. Well, it still was not where I knew this gun to be. LOW AND BEHOLD, I remembered I opened a new tin of .177 JSB Monsters when this problem started. Well, the freshly opened tin has a deeper and narrower skirt. The older(accurate to my gun) is the top and the newer(not so accurate in my gun) on the bottom. The loading probe tip now doesn't sit in the bottom of the skirt well with the newer ones. I bought a whole sleeve like this. I may try to machine down my probe tip to seat in the bottom of these narrow welled newer pellets. But why make a change to design without offering disclosure on the tin? Like, "new and improved!" I pulled a small bit of hair out trying to find out what was wrong with my gun! And I really can't spare any hair!
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