JSB pellet head size ?

Jump to latest Follow Reply
Airbuks

Airbuks

Member
Feb 17, 2016
47
0
Flemish Brabant, Belgium
Hi đź‘‹ ,

can someone explain to me why I buy a tin of 5,52 mm size JSB heavy if all the heads measure 5,50 and the skirts 5,74 mm ?? 

796daa2b5b5166730c49ec91fd99e6f1.jpg

dda794ff5d4f0eec1715ef58e07ef23f.jpg

 
Yes indeed , the weight is one issue that I realized long time ago . That’s why I weigh my pellets for target shooting . The only thing I never checked where the diameters of the pellets . Generally a tin of JSB 5,52 results in much tighter groups then a tin of 5,50 .
whets funny is that almost the whole thin have the same headsizer ( 5,50 instead of 5,52 what the tin says ) but the skirts of each pellet have a much bigger size ( 5,74 ) ? ??? 
 
Upvote 0
Airbuks, I have started several threads on the the subject on different forums sense I started weighing, head sizing ect. about six mo. ago! most of the responses I get are "It's been that way for years" or one like the poster above, some off the wall comment ! I too am very frustrated, when you buy something that is marked a certain size you buy it in that size because that is what you need and want and find it not to be what it was so posed to be it is very disturbing, at least it is to me!! that being said apparently we are a small percentage of the airgun community or things would change!
I always see people complaining about FLYERS on all of the forums while blaming the gun or barrel or them selves in a few instances when truth be told most of it is from poor quality ammo! If they would spend some time and check the POOR consistency of the JSB stuff they just might find it would improve there game tremendously! 
My rifle will only shoot .452 and .453 headed pellets accurately with grouping deteriorating increasingly as the size gets smaller. I have ordered pellets from many of the sellers only to find that the red sticker on the bottom of the tin is worthless! I have given up trying to find 10.34 pellets with a head size of 4.52 or larger after sorting through over 25 tins from various vendors finding less than 1/2 a tin of the correct size 4.52 that was marked on the tin! 
I have found a batch of 13.34 that were all but a very few exactly as marked but being as I shoot field target in the summer so I wont be using them as the FT LB of energy would be to high and the trajectory would suffer anyways. I don't know if its a Quality control issue or bad/worn out tooling but if they can make one size to spec I don't see why some of the others are so far from what they are marked!! Oh Well enough of my ranting ! Good luck I hope your luck finding some good ones is better than mine has been!!
P.S. I even saw a guy looking to buy pellets with 4.52 and bigger heads on one of the sites last week, never saw any responces to his post!! must be rare endangered species!! J.L.
 
Upvote 0
Check out my Field Target Tech Channel videos on U Tube, I describe all of the dilemmas mentioned above, and how to sort and cull them. You also might not be getting accurate readings, due to the use of calipers. I can measure the same pellet several times, and get several different numbers. Calipers are generally not used for accurately measuring headsize.

Tom Holland
[email protected] 
Assistant Match Director 
Eastern Suffolk Competitive Airgunners Association (ESCAA) Long Island NY 
escaaclub.com 
 
Upvote 0
I have found that Air Arms have about the same variance in head size as the JSB'S, but their weight is less spread out compared to the JSB'S. When I have to choose between the two, I'll usually go with the Air Arms. I've also tested the H&N Sniper Mediums, at 8.5 grains, and found a very small variance in headsize, and weights were tighter than both the Air Arms and the JSB'S, but still needed to be weighed and sorted. This is more of a conical design, than the traditional hourglass shape of the Air Arms and JSB diabolo. The only thing with them, is, not a lot of barrels like them, Lothar Walther choked barrels in particular. When a barrel is found that shoots them well, they will buck the wind way better than an Air Arms or JSB.

Tom Holland 
[email protected] 
Assistant Match Director 
Eastern Suffolk Competitive Airgunners Association (ESCAA) Long Island NY escaaclub.com 
 
Upvote 0
DKL, you are absolutely correct in that statement, and I'll take it one step further. As I explained in my Field Target Tech Channel #3, it also has to do with an age old enemy..... friction. A larger head size will probably (but not necessarily) yield a pellet that is heavier than the tins nominal weight. On the flip side, a pellet with a smaller head size, will probably (again, not necessarily) yield a pellet that is lighter than the tins nominal weight. When they hit the choke, they will be sized all the same, and be uniform when they exit the barrel. What will not be uniform, will be their velocity at the time they reach the choke, and when it leaves the barrel. This would be due to a combination of to large/small of headsize, coupled with the light/heavy weight of the pellet. I've run an entire tin of pellets through a chronograph, and got a spread of over 70 FPS. After sorting (weight, head size, and rolling, which weeds out the smaller and larger skirts) that spread was cut to around 13-15 FPS. That 70 FPS variance, is where your radical flyers come from, in all directions.

Tom Holland 
[email protected] 
Assistant Match Director 
Eastern Suffolk Competitive Airgunners Association (ESCAA) Long Island NY escaaclub.com 
 
Upvote 0
As far as H/N pellets go of the 3 tins I sorted out they were much more consistent in weight than the JSB's but all three of the tins I checked all and I mean ALL were 4.49 and 4.50 head size when the can was marked 4.52 ! and by the way I use a" pellegage" not calipers to do my checking Mr. Holland so I do believe I am getting good info. Not bashing H/N but even when I had there pellets in the correct size in the past they did not group as well in my rifle like the proper size JSB's. I have also checked a few tins of Air Arms pellets for friends and they were very consistent in weight but much smaller than marked on the tin!! (4.49/4.50) I don't know why the makers even bother putting the size on the tin if they can't do any better than they are at making them!!! J.L.
 
Upvote 0
JL, I pretty much found exactly what you found, and it seems no matter what company is producing them, it seems to be a crapshoot on what's marked on the tin. Pelletgage is pretty accurate, so your info is pretty reliable, because the Pelletgage is reliable. The caliper comment was for the gentleman in the post that was using them above. Keep sorting, between all of us on this forum, our findings and observations, we are bound to make these companies make a better quality product in the long run.

Tom Holland
[email protected] 
Assistant Match Director 
Eastern Suffolk Competitive Airgunners Association (ESCAA)Long Island NY escaaclub.com 
 
Upvote 0
Mr Holland, I think we are such a small percentage of the airgun community (guys seeking ultimate accuracy) that it probably won't ever change as long as shooters are happy with there results and accept the results they get with the so posed best pellets on the market I doubt things will get any better!! In my search for alternative ammo I bought a tin of 13.34 JSB's to check out for indoor bench rest shooting and I was amazed at the head size accuracy in the tin as almost every one were exactly as marked on the tin (4.52) so I ordered a bunch more from the same lot # and they to were almost all perfect also. I just don't know why if they can make the 13.34's correct why are the 10.34 so far off? Don't know what I am going to do for field target this summer as I have about 10,000 pellets sorted and weight but really cant feel good about using them as they are all smaller than either of my rifles like. I have contemplated making up new barrels from L/W blanks but that's a crap shoot at best as nothing says they will like small ammo either!! 
I'm all out of Ideas and pretty disgusted about the whole thing but I can't come up with a solution, as you have said in your video's to can make em smaller but not bigger!!!
Keep up the good work on your channel maybe if more people try being particular with there ammo it might wake op the makers!! J.L.
 
Upvote 0
JL,

Well said. Unfortunately, you are right. Maybe they can't get the smaller sizes as accurate as the larger .22s and 25s. What accuracy means to one person, might be totally unacceptable to another (probably me!!). I think it is the Achilles heel of the industry. We have 3, 4000 dollar guns with another couple of grand worth of optics on it, and can't get them to shoot one hole groups at 55 yards. But we should. If a company (or service) sold an absolutely perfect tin of pellets, in every way, even if it cost a few bucks, guys like me would at least try them. It would save this guy hours upon hours of time spent screwing with things that should be uniform anyway.
My next endeavor is to get several sets of dies, and swage my own.
Keep on testing, tinkering, asking, and answer every question you can. We'll figure this out at some point!!!

Tom Holland 
[email protected] 
Assistant Match Director 
Eastern Suffolk Competitive Airgunners Association (ESCAA) Long Island NY escaaclub.com 
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu