Pellet variance |
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kruzaroad
Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2284 |
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Posted: 20 Sep 2023 at 8:09pm |
If you've got reeming tool at the size you want you could make a sizer to push them through.
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KiwiTR6
Senior Member Joined: 03 Nov 2022 Location: Stratford Status: Offline Posts: 282 |
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Started having a sort through the tin of 4.52 JSB 'Exacts' tonight dividing them into 4.44 and under on one side and 4.46 and larger on the other (the verniers are accurate to .02mm). I haven't made a lot of progress as you can see but the ratio is about 2:1. The smallest is 4.42 and the largest 4.48 - a long way off the 4.52 stated on the tin regardless. To further demonstrate my thinking re the Air Chief challenge gun, a pic of a 4.42 JSB sitting nicely inside the barrel and another of a 4.52 Sig that won't enter without being forced in. To my way of thinking the 4.42 is going to shoot straighter in this gun than the 4.52. |
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FX Wildcat MK111 BT Sniper .25
FX Dreamline Classic .22 Diana Outlaw .22 Cometa Fenix 400 .177 Weihrauch HW50 .177 Crosman 2240 PCP Custom .22 Crosman 2250 PCP Custom .22 Brocock Grand Prix .22 |
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kruzaroad
Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2284 |
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There's also batch factor. Some batches are all over the place.
When I was measuring through tins, some I started wondering if they just scoop up the reject sizes every once and a while just to fill tins. My sig daggers weren't very consistent when measuring for the sig. Sig hated them. Liked AA deablo which can show inconsistent sizing more than I like. And exact heavy which was a lot better for consistency. Had some gamo magnium couldnt get quite a few in barrel, so gave up on them. Why I weigh and size my hunting pellets. Should buy a die really. |
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RangerPete
Senior Member Joined: 18 Apr 2023 Location: Cambridge. Status: Offline Posts: 884 |
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Interesting thread Kiwi.
I'm impressed with the RWS Superdome! I have never really considered too many brands to be "good". JSB has always been my go to, and I consider H&N to be good (the Germans usually do things right), but most of my guns prefer JSB's to H&N's. All other brands I've usually considered to be cheep and substandard, but i'll have to look into these RWS Superdomes. And after all of your measuring, regardless of what the actual size or average size is in the tin, JSB Exacts 8.44gr in 4,52mm still shoot so beautifully out of most of my guns. I just actually posted a picture of some 10 shot groups with the JSB Exact, JSB Exact Express and Gamo 10X. (posted the pic in the "reviews" section under the review I was doing on the Gamo 10X pellets.) With results like that I cant argue with JSB, regardless of what ever size pellet they are putting into the tins. As long as they dont change anything and just keep doing what they have been doing, I'll be happy |
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Walk quietly, but carry a big stick.
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KiwiTR6
Senior Member Joined: 03 Nov 2022 Location: Stratford Status: Offline Posts: 282 |
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Nunga I was pretty sure I had checked skirt sizes before I started and found they were somewhat larger so I just did the same check on the JSB skirts and nope, that's not the case. Again, a hell of a lot of variance that I wasn't expecting from this manufacturer. |
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FX Wildcat MK111 BT Sniper .25
FX Dreamline Classic .22 Diana Outlaw .22 Cometa Fenix 400 .177 Weihrauch HW50 .177 Crosman 2240 PCP Custom .22 Crosman 2250 PCP Custom .22 Brocock Grand Prix .22 |
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nunga
Forum Moderator Joined: 08 Mar 2013 Location: Pukekohe Status: Offline Posts: 1009 |
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Jsb pellets have always had a smaller head size than stated. I have found they take their size from the skirt not the head on all the tests i have ever done on them
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2nd place HP springer - WFTF World Championships 2014
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KiwiTR6
Senior Member Joined: 03 Nov 2022 Location: Stratford Status: Offline Posts: 282 |
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Now that I've gone as far as I can with the MIC project gun I though I'd buy some smaller 4.50 JSB Exacts to try in place of the 4.52 I've been using. The logic being that a smaller pellet might perform better in what seems to be a tight bore. So I measured some of the 4.52 from a new tin and got some very strange results. Initially I thought it might be my MIC digital calipers so I swapped to my MIJ Mutitoyo vernier calipers and got the same results. I was led to believe from the factory visit video I viewed on Utube recently that the JSB's are sorted in the packing centre to very exact sizing, hence the 4.50, 4.51, 4.52 packs. I'm either missing something obvious or that was a complete crock!. Perhaps their QC has gone down the sink since Covid but what I recently bought as 4.52 are nothing like it. So to confirm my suspicions, I checked four different brands in .177, taking 10 pellets from each tin in sequence and measuring them with the Mutitoyo calipers. I don't have full details of the Sig pellets, they're just some that Dave Simms gave me to try a while back. The differences are astounding as you can see from the results attached and in the future I won't be so keen to buy the JSBs - although having said that I may buy a tin of the 4.50 and select the smallest from them to try (assuming they will actually be smaller than the 4.52 average of 4.44). I'm guessing they'll be just the same mix with a different size written on the tin! I have plenty more that I could check but it's pretty brain numbing so I leave it at that for the moment. |
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FX Wildcat MK111 BT Sniper .25
FX Dreamline Classic .22 Diana Outlaw .22 Cometa Fenix 400 .177 Weihrauch HW50 .177 Crosman 2240 PCP Custom .22 Crosman 2250 PCP Custom .22 Brocock Grand Prix .22 |
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