What is up with JSB?

Very different molds. Nothing to offer other than this is why I buy cases when I can. Still no guarantee to them all being the same but so far it's worked for me. Fewer times I need to re sight the scope...

Whoa. The geometry is totally different.

Either those tins were miss-labeled or the JSB Exact Jumbo .22 15.89 domes

were given a full blown re-design.

Matt

I came across these a year ago. They were in .25 cal. Sent the pic to JSB and asked them what was going on. Never did reply to me.

Oddly enough they were the same weight and at 25 yards they shot the same.

Unfortunately PA doesn't let JSB put the lot and die information on the tins anymore. Has the accuracy changed or only poi? If it's the poi then like you said re-zero and carry on.

I'll put it to you like this...

If any of you have questions or concerns then contact me and I'll get an answer for you. Have a nice day.

Joe

A friend of mine just recieved some 16gr and has the same issue. I would get ahold of someone on this issue. Quality control issue? 

We're soon going to see swaged slugs with more precision, and JSB will either have to lower their price, or get their act together in QC

Monkeydad1969, or Joe, you posted as quoted below. Thank you! I assume from your icon that you are with Predator International? If you have any illumination, many of us would benefit.

If any of you have questions or concerns then contact me and I'll get an answer for you. Have a nice day.

Joe

There used to be small adhesive labels on the bottom of JSB tins. 

They are sometimes still present, but in many cases either removed or covered by another label. Generally, it has become more difficult to know the specific head diameter of JSB pellets, or their lot and date coding. I have no confirmation of any actions by dealers or distributors to remove the labelling, but it is not there in the product that I have most recently purchased - through authorized distribution channels in the US. Preface this, for many years, I have used JSB and AA for all my competitive shooting, and most all my friends do as well.

It's significant to keep these labels and the lot traceability that they permit. They included the nominal head diameter, in X.XX mm format. As a customer, I want to have/know that data. In my experience, the JSB (including private label brandings) pellets are without any doubt the most widely used field target and benchrest pellet, and they doubtlessly have capability to ship a high quality product. There is nevertheless variation in current production by many reports. This increases the concern if lot tracking and head size to the ten micron variance, as shown in published specifications for many years are to be obscured.

European BLOGS have described what these labels encoded and represented. I copy and repost in italic.

copied from a public posting dated September 25, 2016 on Airgunforum.co.uk

here is a quick explanation to hopefully help
below the label reads 46560015 7 4.52
always work from the right on the main code
1. the last 2 numbers indicate the year in this case 15 indicating 2015
2. the 2 prior numbers indicate the quality control employee number 00 in this case
3. the 2 numbers before that is the production line employee number 56 in this case
4. the 2 before are the all important die number which on this tin is 46 
please note you always work from the right cos if you get to step 4 and only 1 number then that's the die number IE dies 1-9 
the 7 below would indicate the batch number 
and then finally the 4.52 is the claimed size 

in general the number that matters on JSB exacts it the Die number (please note there was some bad batches in 2015 on various dies)

if you purchase your JSB pellets from anyone OTHER then Umarex/Pyramyd you will get the tag with the die # info

that is IF they did not get theirs from Umarex/Pyramyd

I ran into this issue, same as Mike L in his post , a few above. One sleeve of .25 JSB's were one style, and the next sleeve were the other style. Luckily both shot the same in my Cricket, so never pushed the issue.

if you purchase your JSB pellets from anyone OTHER then Umarex/Pyramyd you will get the tag with the die # info

that is IF they did not get theirs from Umarex/Pyramyd

Click to expand...

Why don't they sell them with the tags? do they remove them or request the manufacturer not put them on and for what reason?

5.41 are you sure ? That's oddly small and don't see how those could be accurate. 

The 15.89s I just received are measuring 5.52 and they have the narrow deeper skirt like the ones in your pic. and the 18.13 I got are at 5.51....

I also bought some AA 18 grainers and there at 5.53 with a few at 5.52

I'm measuring with a digital caliper...

James from Michigan, 

I've corresponded with quite a few airgunners who have related surprising results regarding pellet head diameters.

However, JSB Jumbo pellets at 5.41 is extreme. Nominally, JSB only makes .22 caliber (5.5 mm) in three head sizes, 5.50, 5.51, 5.52 mm. See:

http://www.schulzdiabolo.cz/en/pellets/exact-jumbo-22/

So, your outdoorman must have had a stock of "undersized" pellets. I suppose that the entire question of variances in pellet head size favors the idea of Pelletgage. There are many reports of unexpected variance and enough reports of consistent shifts from the nominal expected size to make all of us wonder.

I suggest that some dealers are happier with the idea of just calling them 4.5 or 5.5 mm and downplaying any specifications, labelling, or marking that allow variances to be called deviation. It is the manufacturers who have perpetuated giving them nominal head sizes, and selling the concept that they offer choices.

One generalization is that the target wadcutters are produced for 10M shooters with more control over this criterion. The demand for pellets that have better consistency and better ballistics is somewhat new (new, meaning less than one generation). With benchrest shooters having serious competition at ranges to 75 yards and beyond, it creates demand for a higher level of quality in both the rifles and the ammunition.

I hope that manufacturers, distributors, and retail dealers will cooperate to meet this demand. Having lot control traceable to the end user is a fundamental way to measure this.

Wow, the JSB 15.9gr is one of my favorites and I have been keeping records of head sizes since 2012. I’ve never gotten a tin that measured under 5.48mm (0.216in) but even that is considered severely undersized. A tin measuring 5.41mm (0.213in) would be considered by most to be a gross lapse of JSB’s quality control.

I’m inclined to think the calipers are reading low, so perhaps we are not getting an accurate absolute reading (e.g. 5.41mm) but the relative difference of 0.09mm would tend to be a reliable figure. Still, that’s a massive difference and would certainly make one of them either very loose or very tight. My guess is the 5.50mm is actually more like 5.55mm and that’s why they are so tight.

It might be interesting to measure a 1/4” drill bit shank (a spot undamaged by the drill chuck). It should come in at 0.249” to within a half-thousandth, or metric 6.32mm +/- 0.01. That would help establish confidence in the readings. The calipers may just need the the spine screws snugged up to take out a little free play.

For what it’s worth I’ve noticed these fluctuations in inner skirt Dia. Thickness of inner edge & taper & what I call the “SOCKET” of the skirt... used to get all up tight about it ( even commented about it on this forum a year or more ago!)but for my own satisfaction accuracy seems to center more around head Dia. & shape-condition for my purpose’s the greatest differences seems to be the .177 monsters (old style!) the redesigned seem more consistent but don’t shoot as accurately in two of my LW barrels 3rd barrel jury’s still out?, more testing... by the way have noticed it in.22’s also? Only 2 calibers I shoot

Sorry, I don’t mean to poke a hornet’s nest but a few of us were understandably perplexed by a 5.41mm measurement. I agree the main takeaway is a 0.09mm (0.0035in) delta from one batch to another.

It’s particularly interesting to me because I have never seen anything remotely close to that spread in 6 years of buying not just quality brands like JSB and H&N, but even mid-range brands like Crosman. The only example that bad I have experienced was some dirt cheap Daisy pellets. I was once and done with them based on that, and if I were to see the same thing from JSB, I would most definitely want to engage them about it, armed with accurate measurements.