What is up with JSB?

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Gentlemen

it is NOT unusual at all

i shoot benchrest USARB and i purchase pellets every month looking for the best ones

i air gauge my pellets so my accuracy is 10 times more accurate then the normal accuracy discussed here

for instance just in the JSB 8.4g i have some tins with 4.45 heads (too small) and tins with 5.55 heads (too big)


 
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Thanks for that, strever, you’re definitely catching some outliers that I’ve never encountered. A range of 4.45mm – 4.55mm is shocking. I suppose there may be an occasional peewee mixed into my tins but you are describing entire tins that average that small…and then other complete tins that average vastly larger. That’s not good. All the ones I’ve gotten over the years (2012 – present) have fallen into much tighter range, but the more surprising thing is that I haven’t even seen that much deviation in the lesser brands.



Is it safe to say you get poor results with the ones out at the extremes? Or does it work out that sometimes they buck the conventional wisdom?
 
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Oh okay thanks. I misunderstood you. I thought you were saying you sometimes ran into whole tins that averaged 4.45mm or 4.55mm.



Outdoorman was not describing occasional outliers though. He’s talking about two tins whose average head sizes differ by 0.09mm. The former is something I reasonably expect from a 2-3 cent item that gets molded by the millions. However the latter implies a more systemic problem like the molds themselves are made wrong, and represents a severity I’ve never run into with any pellet manufacturer worth their salt. So yeah, I’m still thinking it would be a good idea to engage JSB about it.
 
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Strever, that's very interesting. I've had a general feeling that the AA pellets are more consistent, but I have also seen big variances in a few tins. I tell people that my own criterion is that the mean size of the pellets in a tin should be nominal +/- 0.01 mm and that the variance within a tin should not exceed +/- 0.01 from mean. I consider this loose, but anything better is beyond current manufacturing capabilities. So, that would mean I get a tin of 4.52 JSB 10.3's (my favorite) and check a sample of 50, and they should all be between 4.50 and 4.54 - but not exceeding 0.01 from the mean size found for that tin. Since no pellet manufacturer has ever stated a tolerance, that's just my expectation. I've seen perhaps 20% of the tins that will not meet that criterion, usually due to having a few undersized pellets in the tin. As you say, the undersized ones tend to be fliers. 

There is a statistical basis for saying that the 10% sample size with +/- 0.01 mm limits should have no more than one outside those limits, at a 95% confidence level. But even so, having a 5% chance of using that tin and still having a flier motivates people like you and me.

I wish JSB or H&N would undertake calculation of their Cpk and providing us with a real tolerance and used statistical controls in their production. I have had thoughts of an automated optical inspection machine that could really sort them in mass volume. The cost would likely be in the $300K range. Barcode reader cameras can resolve these sizes, they are used in the machines that place electronic components on circuit boards in automated assembly lines. My belief is that they depend on human operators with calipers, and that just won't do it.

Do you have a Pelletgage? I think the air gauges have some interesting advantages, as they give a direct indication of the airflow restriction in the collet. However, they don't really tell you the size directly and may have more "precision" than accuracy. I have produced some PG that have 4.480 to 4.525 apertures in five micron steps. I check apertures in every lot with class X plug gages, but it is true that there is a ten micron step between the apertures in a regular Pellegage. 

Of course, with a compressor, loading press, various hoses, valves, and fittings, an air gauge might require an investment of about 20X the price of a Pelletgage and a dedicated bench, but more power to you, and thanks for telling us about your findings.

regards,

Jerry
 
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yes i have some tins that average extra small 4.45 and i have tins that average extra large 4.55
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Wow, that’s just awful. I’d want my money back!

Has that happened often enough that you’d call it a common occurrence?

I figured I had given enough money to the pellet industry by now to see the worst it has to offer. My wife certainly thinks so. Oh, and O-rings. I have a lot of O-rings. :)
 
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we all have lots of O'rings because they are sooo inexpensive from the O'ring store we buy a cpl dollars of each size :)

this last year 2018 the trend for the 8.4g was small and i got the 4.45's last year, the 4.55's was in 2014

for the heavier pellets like the 13.4g and 16.2g the trend is too large



yes i have some tins that average extra small 4.45 and i have tins that average extra large 4.55
Click to expand...

Wow, that’s just awful. I’d want my money back!

Has that happened often enough that you’d call it a common occurrence?

I figured I had given enough money to the pellet industry by now to see the worst it has to offer. My wife certainly thinks so. Oh, and O-rings. I have a lot of O-rings. :)
Click to expand...


 
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Jerry

i have both .177 and 22 from your very first run and the .177 i have changed the size written on the holes twice and i have not had a use for the 22 yet

yes i now have pins to check hole size, the first time the size change was because someone on a forum said what to write, 2nd time was what i found with the pins.

the Air gauge i have i did pay 20x but there has been someone building them last cpl years for approx 8x, not sure if he still is

i agree with you and wish the pellet mfg's would give us a tolerance and hold it



Dick Strever




 
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Joe

do you have a polygon barrel and looking for 13.4 pellets ?

the 13.4 new design run too large for most of us have you tried some ?



Dick





Pelletgage,I use your products in .177/.22 not sure which production run? I’ve had good luck with them, never tried an air gauge! At this point don’t know if I ever will? My biggest issue is finding pellets in 4.54 or larger for my barrels, that’s what they prefer...
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I love my 12 groove!, when I ordered my Tm from Martin I asked then if it would shoot the 10.3’s and he told me no problem will even shoot the 13.4’s if I wanted the Reg. Set for those? I said to just set it for the 10.3’s and glad I did, but I tell you dick I must have one of those barrels cause it shoots everything! Cp’s, all 3 weights of jsb’s? It’s not fussy, If I could only do it right... ( something I want to pass on to you and others I had a conversation with Martin when I ordered my BM about barrels and this he reiterated more than once that the poly’s are no more accurate than a 12 groove, except when the wind is blowing! and I knew what he meant, as do you! (Now this was all in the context of 25m) SORRY! don’t want to high jack the thread to be about barrels but must admit the two go hand & hand...
 
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Pellets produced by JSB in Czechoslovakia are the highest quality overall, and the overwhelming choice of most benchrest and field target competitors for the last decade or so. Since I began shooting airguns, I have not found any that are better.

That said, they are imperfect, and many serious shooters go to great lengths to find JSB pellets from different lots that are "liked" by their guns. I have attempted to understand all the reasons behind this complexity.

JSB is a pretty small company, notwithstanding. It appears that they have about 100 employees, and 20-30 of them are involved with manual inspection and sorting. 

Hard Air Magazine published a nice online story about JSB in June, 2016, and another good article about the names and labels they use. 

Airgun Web TV has an https://www.youtube.com/watch?v=dbHqPbMHAmM with the US Distributor for JSB, Predator International at the 2018 Shot Show.

Steve Scialli of Airgun Exploration and Advancement Channel had an https://www.youtube.com/watch?v=5OQpiwYS8C8&t=316s at the IWA 2018 show, and discussed the operations at JSB.

Further insight:

JSB produces a "Premium" pellet, specially packaged and selected a few years ago (circa 2015). These sell for a "premium" price, too - $15 for a 200 pc tin. The fact that JSB themselves are doing some special selection seems to reaffirm that it can be productive to do some sorting.

Hard Air Magazine reviewed this pellet, and Tom Gaylord published a BLOG on the Pyramyd Air website in August, 2015, and also a BLOG post about the "Premium" pellets. Giles at Airgun Gear Show also published a https://www.youtube.com/watch?v=mo3U9TVcotA. 

So, if you checked all these links, you know "what is up", at least to some extent. I believe that the issue is one of process control. JSB does have a degree of control, but they depend on manual visual inspection to a great degree. They have expanded production rapidly, and they have new equipment being used. The number of presses and die sets is great, and the tooling changes are extensive.

It seems that they do sample pellets from each lot, and they test these by shooting groups for a maximum of 5 mm at their inside range. This is an interesting idea, and should have merit. Even so, the group size limit is close to 2 MOA.

I am speculating that the 0.01 mm changes in head diameter are not based on specific tooling for a planned diameter, but on a sorting "binning" that reflects process variations during continuing operations. It hasn't been shown that any manufacturer has better process controls, and the end result is that many users are doing their own inspections and "binning". 




 
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Quite honestly I believe because each barrel is different in what head size/shape, weight profile etc. it prefers?, I wish JSB would just produce/offer head Dia. Pellets on the large end of spectrum, say 4.55 (for .177) and let the customer size his pellets to his barrels desired Dia. I’m thinking mainly for competitors in BR-FT etc.? Just a thought...
 
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