Eley match consistency

King_beardsly said:

How consistent is Eley match across the board, I had a lot that shot lights out but I’m essentially out and need to order more. Unfortunately the lot isn’t available anymore and I can’t track it down on the secondary market. Issue is living in NY makes lot testing a pain since ammo must got the an FFL to transfer and unfortunately the fee isn’t cheap per transaction weather it’s one box or a pallet load.

So my question is, can I get away with just ordering a lot that a similar speed to my current one and pray it’s good or attempt to lot test then hope it’s still available once I know it’s good.

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I here shooters say . My gun likes slower ammo and others say just the opposite. I have not found that to be the case when lot testing ammo that offers different speeds such as Eley and RWS. It's all about the lot numbers and different machines they are produced on. I Pay very little attention to speed when lot testing Eley.I have found good lots of both faster and slower. If you can't buy multiple lots to test it's really a crap shoot whether it be Eley, Lapua ,RWS or any other 22lr ammo.

I recently bought a buddy of mine’s entire stash of Team. My understanding is that Team is one level down from Match in the Eley flat nose lineup.

I shot a total of 6 lots at 50, 100, 200, and 300 yards (I used a minimum of 50 rounds per lot). Per my notes, only 1 lot was “meh” while the other 5 were very strong contenders to displace my dwindling supply of Eley Practice 100. The SD I was seeing was consistently in the 6-7 fps area where my center X rarely goes below 9. Velocity differences did vary from the fastest lot being 1127 to the slowest at 1090.

Ammo is always a crap shoot. But my experience is with the high quality eley stuff is that if your gun likes it - it will like it all. My vudoo shoots it well, but has intermittently ignition issues. My RimX shoots it without any hiccups at all. So the vudoo is fed Lapua/SK in matches.

I just splurged on 6 bricks of Tenex. The current plan is to go test on Wednesday. Hoping for continued awesome results from that lineup.

Looking at the meh lot - it was near the slower end of the range out of the 6 I shot. But it wasn’t the slowest. The faster stuff did shoot really well (all chrono’d over 1100fps). This is out of a RimX with a 20” proof completion contour barrel, with a Bix’n Andy TacSport pro trigger. Shot off of a bench with a bipod and rear bag.

Good luck!

Stating the obvious because you ask.
Lots very. Some more than others. Some rifles are more lot sensitive than others.
That being said I have found Eley in general and Eley Match in particular to be among the most uniform of the rimfire ammo. I was embarrassed to say my rifle often shoots Match better than Tenex. I mentioned it to a serious BR friend and he found the same thing.
@justin amateur has often mentioned poor lots of Eley in his rifles. I don’t doubt it at all. Justin is a very factual guy. I am yet to run into a truly bad lot.

I would think the worst lot you can find will do well at PRS

Eley Match, according to an email from Eley customer service,
are the same cartridges as Tenex, that didn't test out to the standards expected from Tenex.
Due to the method of statistical sampling used at the factory, you can purchase Eley Match
that is better quality than those labeled Tenex. It really is the assembly line lottery.
I've had Eley Match with an ES of 26 fps for 50 shots that produced extremely good results at 200 yards
and the next brick delivered chronied an ES of 60 fps and spit vertical strays.
We pays our money, we takes our chances.

At 200 yards 60 FPS will disperse approximately 6” due to velocity alone.

King_beardsly said:

So my question is, can I get away with just ordering a lot that a similar speed to my current one and pray it’s good or attempt to lot test then hope it’s still available once I know it’s good.

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I cannot answer this directly, but I offered some Center X to a guy on Rimfire Central who inquired. I had a surplus of one lot. His stipulation was slower speed with 23-25 first numbers. Which I replied, I have never owned a lot # under 25.
Blah, blah, sold him 8 bricks, but through conversations, and a little research, I came to the conclusion he knew what he was doing.
So there it is, a conversation with a stranger, huge assumption and a big thumbs up to your plan!

King_beardsly said:

How consistent is Eley match across the board, I had a lot that shot lights out but I’m essentially out and need to order more. Unfortunately the lot isn’t available anymore and I can’t track it down on the secondary market. Issue is living in NY makes lot testing a pain since ammo must got the an FFL to transfer and unfortunately the fee isn’t cheap per transaction weather it’s one box or a pallet load.

So my question is, can I get away with just ordering a lot that a similar speed to my current one and pray it’s good or attempt to lot test then hope it’s still available once I know it’s good.

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You might get close if you get a Lot at a similar speed and from the same machine. Otherwise, it's down to the Lot testing from that machine that your rifle likes.

RTH1800 said:

Stating the obvious because you ask.
Lots very. Some more than others. Some rifles are more lot sensitive than others.
That being said I have found Eley in general and Eley Match in particular to be among the most uniform of the rimfire ammo. I was embarrassed to say my rifle often shoots Match better than Tenex. I mentioned it to a serious BR friend and he found the same thing.
@justin amateur has often mentioned poor lots of Eley in his rifles. I don’t doubt it at all. Justin is a very factual guy. I am yet to run into a truly bad lot.

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I can say that happened to me too. I shot 4 boxes of match and decided it shot pretty good, I wonder how much better Tenex is? It was almost as good. The match shot just slightly better. Very small sample size, but sam conclusion.

I had so much variation in lot quality between consecutive orders, I contacted Eley.
Asked about their method of lot grading. The explanation is statistical sampling.
A small portion of each batch is tested from fixtured barrels in a tunnel.
The results from the small sample determines how the run is labeled.
I asked about the sample sizes and confidence levels used in the determination,
and was informed that it was proprietary information not to be disclosed.
Considering I had Eley Match and Eley Team that produced better results/chrony numbers than Tenex,
it tells me that the method of statistical sampling being used, may not be as effective as advertised.

Or....ammo degradation occurs during shipping from England to the US.
Those cargo containers aren't insulated and it's a long trip by freighter across the Atlantic.
And the drivers/handlers at FedEx and UPS aren't the most careful folks with packages.

Every make of match ammo -- Eley, Lapua, and RWS -- will have lots that have different average MVs.

Regardless of match ammo manufacturer, the average MV of a lot is not related to how it performs. In other words, it doesn't matter if its "slower" or "faster". What matters is how it shoots, and that isn't determined by the average MV produced in a manufacturer's test barrels.

In good barrels, shooting performance is primarily related to ammo consistency -- small ES, consistent loading in terms of components, priming, crimping and bullet characteristics. Variation in bore characteristics from one barrel to the next mean consistent lots will do better in some barrels than in others.

The grade of a match ammo -- whether, for example, it's Tenex, Match, or Team -- isn't a guarantee of its performance over the chronograph or on target, suggesting other factors may also be involved in grading.

grauhanen said:

The grade of a match ammo -- whether, for example, it's Tenex, Match, or Team -- isn't a guarantee of its performance over the chronograph or on target, suggesting other factors may also be involved in grading.

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Which is why, to me, the sensible way to go about acquiring an optimal lot of ammo is to send the rifle off for lot testing. Killough Shooting Sports tests Eley but only out to 50 meters and it isn't clear from this description whether they will test labels other than Tenex.

I see this as a shortcoming compared to Lapua's test centers, which test at 50 and 100 meters simultaneously. When I sent my Vudoo to Mesa,I had a lot of Center-X that was great at 50m, but comparatively poor at 100. I ended up buying two cases (pre-pandemic; there is a 1-case limit now) of a Center-X lot that did well at 100m and it has served me well in matches out to 400+ yards.

This lot also does well in my newly-built RimX, but it pales in comparison to the 1/2-3/4" groups out of a single 50-round box of Tenex I got from a buddy. A box of Tenex from another buddy did more like my Center-X.

Ahhh, the rimfire lottery.....

DownhillFromHere said:

Which is why, to me, the sensible way to go about acquiring an optimal lot of ammo is to send the rifle off for lot testing. Killough Shooting Sports tests Eley but only out to 50 meters and it isn't clear from this description whether they will test labels other than Tenex.

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They only test Tenex on the Eley test range. Minimum purchase is 2500 rounds (1/2 case). No other grades / brands are tested at this facility.

1813Benny said:

They only test Tenex on the Eley test range. Minimum purchase is 2500 rounds (1/2 case). No other grades / brands are tested at this facility.

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You may be correct, but I seem to recall they tested Match as well in the past. When Vudoo rimfire rifles first came out I had 3 sent directly to them for testing. I think they tested both Match and Tenex but am not certain.

grauhanen said:

The grade of a match ammo -- whether, for example, it's Tenex, Match, or Team -- isn't a guarantee of its performance over the chronograph or on target, suggesting other factors may also be involved in grading.

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No disrespect intended here but I think this simply indicates insufficient rigor in the grading process and the challenges of grading 22LR ammo.

Eley's lot analyzer program was before my time but I think it's failure demonstrates that they were unable to get a handle on significant factors affecting ammo performance. The same goes for all of the manufacturers in my opinion.

If you test every round in the lot, you have nothing to sell.

RTH1800 said:

If you test every round in the lot, you have nothing to sell.

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Difficult to disagree with your logic there.

I don't know what percentage of a lot would have to be expended in order to achieve an acceptably reliable grading system. Would that be 2, 3 or maybe 5 percent? What if it was 5 and they spent another 5 to do the testing (it wouldn't be that much). I would readily pay an extra 10 percent for my SK RM to insure that I didn't get a case of below average Standard Plus.

The above argument doesn't apply when I buy Lapua because I only have a CenterX budget. Since it is the lowest grade I can only gain when some Midas falls through the cracks.

Quality control though statistical sampling is an interesting read.
Sample sizes are determined from the total number of items in the batch,
based on the level of confidence required and the allowable defects/severity of defects per thousand.
It is surprising how small a sample can be tested, and still be called quality control.

I played with an online calculator.
A 95% confidence level from a batch of 5000 cartridges was less than 400 cartridges tested.
An 80% confidence level and you can get away with testing less than 300.
So you go to the factory test facility and you purchase a couple cases by testing how many? 40? Fascinating.


Welcome to the assembly line lottery....ya' pays y'er money, ya' takes y'er chances.

Killough's has tested Eley Match (Black Box) in recent times (3Q 2022) based on some ammo and related paperwork I have in the closet. People are buying blindly whatever ammo they can find in hopes of finding a good lot, as very few people in the general shooting public have the luxury of time to lot test as was done in the past. If your equipment doesn't like it or doesn't shoot to your expectations, sell and buy more is the general rule now. JMO

Williwaw said:

No disrespect intended here but I think this simply indicates insufficient rigor in the grading process and the challenges of grading 22LR ammo.

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There should be no doubt at all that the match ammo grading process is insufficiently rigorous to accurately grade all production runs. It helps explain why ammo performance isn't necessarily equal to its cost.

Unfortunately there's no information published to confirm exactly how the ammo grading is undertaken by any of the match ammo makers. It's proprietary and kept secret.

The question remains: is grading by test shooting the only means by which manufacturers grade production runs? There's room for doubt.

Whatever the grading process includes, it is clearly not enough to eliminate lots of top tier ammo that perform relatively poorly, both over the chronograph and on target. It shouldn't happen but it does. That in itself indicates that factory testing by shooting a fraction of a lot to determine its grade is statistically inadequate.

At the same time, whatever the grading process includes, it results in some lots of lower tier grades of ammo outperforming top tier grades (e.g. Match or even Team outperforming Tenex; or M+ or even CX outperforming X-Act) across many barrels both over the chronograph and on target. If the grading process involved only testing by shooting, that shouldn't happen often, if at all, but it does.

But more than that, grading by test shooting is very time consuming and often results in indeterminate data. Not every lot of ammo -- whether top tier or not -- does equally well in each factory test barrel. In short, the results are often unclear.

Both these of these factors -- statistical inadequacy and time consuming indeterminacy -- are all the more reason to think that something in addition to testing by shooting is involved with grading.

The following are questions for which the answers remain unknown. Is it possible that grading a production run includes organizing it so that the top lots of components -- casings, bullets, propellant, and priming comopound -- come together at certain points in the run? If the loading machines produce better results at some points in the production run, could this be taken into account as well? With decades of experience in producing match ammo, is it possible that factors such as these have a role in determining what grade a lot of a production run should have?

Testing ammunition....how hard could it be? Right?

Lemme think here....it's an exercise in OCD...that I can do.


A run of cartridges is made. Guys on the line tell me its 16,000 cartridges.
I go to my handy dandy quality control calculator and punch in the total number of cartridges,
the level of confidence the bean counters find acceptable, the number of defects per thousand allowed,
the level of severity of the defects and hit enter. Out comes a number.

16,000 items, level of confidence required 95% +/- 5% = size of sample to be tested = 376


So I pull 500 cartridges from the run and wander over to the testing tunnel.
4 concrete benches, each with a bolt action receiver affixed in a jig with a 24 inch match barrel from Walther.
It's a 50 meter tunnel with a computer run recording system that documents muzzle velocity and trajectory location at 50 meters.
Fire up the computer and send 25 to prime barrel 1.
Then hit record and send 4 groups of 25.
Repeat for barrels 2, 3, and 4.

So I've documented 16 groups of 25 shots at 50 meters.
If the outside to outside dimension of all the groups is under 16 millimeters, that's the magic stuff.
If outside dimensions hit 18 mm, that's good enough for local competitions.
20 mm and most folks will blame themselves, or the rifle didn't like that brand.
22 mm of spread is labeled as practice ammo.

Vertical spread is compared to chronograph numbers to confirm cause.
Odd strays indicate component or assembly defects.
The number of outliers is compared to the QC standards found acceptable by the bean counters.
If the number of strays is less than the desired metric, box it, ship it, sell it.
We'll never know the difference, right? It was the wind....I pulled that one....too much coffee.

justin amateur said:

So I've documented 16 groups of 25 shots at 50 meters.
If the outside to outside dimension of all the groups is under 16 millimeters, that's the magic stuff.
If outside dimensions hit 18 mm, that's good enough for local competitions.
20 mm and most folks will blame themselves, or the rifle didn't like that brand.
22 mm of spread is labeled as practice ammo.

Click to expand...

The hypothetical batch comes off the production line that produces match ammo. That's one lot of ammo. Is its grade determined solely by shooting?

With both Eley and Lapua the entire production run putatively begins as Tenex or X-Act. Since the production run obviously isn't equal, it is "downgraded" by the grading process (whatever that is) to be something else. For Eley, it becomes Match or Team. With Lapua, it becomes Midas + or Center X. There wouldn't be anything the manufacturer calls "practice ammo".

If the grade of the lot is determined solely by it's performance over the chronograph and on the target, it doesn't seem to adequately explain how a lot gets labeled as top tier when in the field with a good barrel it may shoot poorly both over the chronograph and on the target. How can that happen? It's a question asked by anyone who has had poor chrony and target performance with a lot of top tier ammo in an otherwise good rifle.

Focussing only on the top tier grades, there are significant implications linked to the idea that grading is done soley by shooting. It suggests several important things.

One is that chronograph results for the same lot of top tier ammo can vary significantly from one good barrel to the next. That is to say, in one barrel the top tier lot can produce a small ES and SD, while in another both are poor. Another, is that it suggests that a lot that does very well on target in one good barrel can also do very poorly in another.

Is it possible for a lot to have such unpredictable behavior so as to be both good and bad at the same time? Or is there that much variability between barrels that produce good results that they can cause the top tier ammo to have such Jekyll and Hyde behavior?

I've had good luck with it. But it's rimfire ammo so it's always a "who knows?" I think.
The better quality ammo you buy the better chance you will have that your gun shoots it well.

Is there that much variability between barrels that produce good results
that they can cause the top tier ammo to have such Jekyll and Hyde behavior?

Nope, not with barrelled actions in a test tunnel.
We've all seen the Jekyll and Hyde Syndrome from a single box of 50.
There's that much variation in assembly and components.
Put 4 shots in one hole, the next hits low or high.
No change in the set up, just a non-conforming cartridge.
Folks like to blame the rifle for preferences due to poor results.
I've found there's a more reasonable answer....lack of uniformity in the cartridges.
This is an assembly line product we are discussing.
Multiple components being manufactured from a variety of materials,
then put together on a production line run by hourly employees.
Between mechanical tolerance slop and component variations,
lack of uniformity in results should be expected, not a surprise, right?

Add in statistical sampling to grade the lots, 400 shots to define a run of 16,000
sounds like there's plenty of room for problems to slip through what's being called quality control.

justin amateur said:

I've found there's a more reasonable answer....lack of uniformity in the cartridges.
This is an assembly line product we are discussing.
Multiple components being manufactured from a variety of materials,
then put together on a production line run by hourly employees.
Between mechanical tolerance slop and component variations,
lack of uniformity in results should be expected, not a surprise, right?

Add in statistical sampling to grade the lots, 400 shots to define a run of 16,000
sounds like there's plenty of room for problems to slip through what's being called quality control

Click to expand...

The explanation offered above makes perfect sense for entry level match ammos (e.g. Eley Club and Target and SK Rifle Match and Standard +) and lesser quality fare where there may well be indifferent assembly of indifferent components by indifferent workers. The goal is quantity with some quality.

In a match ammo production run, components are sorted pre-production by their quality and in production loading machines are fine tuned is a matter of course. This care explains the very small sizes of many lots of match ammo. The goal is quality with some quantity.

To use the example provided, a random sample size of 400 out of 16,000 (2.5% of the total) gives a 95% level of confidence that the sample is reasonably representative of the rest of the population. That is a high level of confidence and it's time consuming to obtain. A shooting-only method of grading ammo would therefore be reasonably reliable in predicting the performance of the entire batch of ammo.

The problem remains that a shooting-only method of grading doesn't explain why some lots of Tenex or X-Act do indeed perform poorly -- not just on target but over the chronograph. If it has indeed been tested by shooting a sample, that shouldn't happen.

It seems doubtful that .22LR match ammo is graded by a shooting-only method. For entry level match ammos, variation within a lot is often so great as to make grading by shooting-only irrelevant.

I ran into problems with Tenex, as did a couple benchrest competitors at the local range,
it caused me to contact Eley to ask about the grading process. According to the response
from Eley, results in the tunnel do make the final decision regarding labeling. The best results
are labeled Tenex. All the other inspections done during manufacture cull obvious problems,
but target results indicate if all the cartridge variables work to produce uniform trajectories.
I could not get an answer regarding the sampling process or acceptable defects per thousand, level of confidence applied.
With multiple shooters finding problems with Tenex, it has me thinking that the level of confidence is lower than 95%
and the acceptable defect rate is higher than we would like. Smaller sample size with a higher number of defects per thousand,
means that boxes of Tenex being less than stellar will happen/have happened.
It's a business....profit is job one. Quality is important as long as it doesn't interfere with profit.

That's my explanation. Without access to the actual testing process, it's the theory
that fits the differences in results from what should be Eley's best. Your thoughts?

It should be expected that all match ammo makers would provide a grading by testing-only response. Since grading and manufacturing processes are kept to themselves, they would not publicly acknowledge anything else.

Is it realistic to believe that with decades of experience the ammo makers don't have a good idea where in a production run to expect the best and worst batches of ammo? They are careful to sort the components -- e.g. casings and bullets -- into their own lots by quality. Are there no trends in a production run that ammo makers can anticipate?

More specifically, is it realistic to say that the various lots made in a production run are, one after the other, completely random in quality? To elaborate, is it likely that a lot of what will shoot very well across many rifles will be just as likely to be followed by a similar one as by one that shoots poorly in every respect?

Is it instead possible that the match ammo makers have a good idea, based on decades of experience, how to load the components so that the best of them should arrive at a certain point in the run to produce what should be the best lots of ammo? Is it possible that testing by shooting small quantities of some lots or every lot could then be used to give some level of confirmation? This would reduce significantly the time consuming process of testing by shooting sample sizes that are sufficiently large to have a reliabe, high level of confidence.

With small sample sizes tested, poor lots of Tenex or X-Act may slip through the cracks. Lower graded lots may turn out to be better than expected. Small samples tested by shooting they can be too small to have a high level of confidence. Results can easily be unreliable. Lots that are expected to be good ("this should be Tenex" or "this should be X-Act) may not be good at all and lots of what should be Team or CX may be better. If most of the production run turns out as expected, all is good.

grauhanen said:

Is it realistic to believe that with decades of experience the ammo makers don't have a good idea where in a production run to expect the best and worst batches of ammo? They are careful to sort the components -- e.g. casings and bullets -- into their own lots by quality. Are there no trends in a production run that ammo makers can anticipate?

Click to expand...

If this were so I would expect that someone here would be able to give another example from another field where such an approach is used. I haven't been able to think of one. Anyone?



I recently viewed some content that Eric Cortina had uploaded of a tour of Berger Bullets. They too were awfully circumspect about their processes but one thing apparent was that they plain reject some of what comes off the line. I have never heard of any of the 22LR manufacturers having a similar practice.

justin amateur said:

Is there that much variability between barrels that produce good results
that they can cause the top tier ammo to have such Jekyll and Hyde behavior?

Nope, not with barrelled actions in a test tunnel.
We've all seen the Jekyll and Hyde Syndrome from a single box of 50.
There's that much variation in assembly and components.
Put 4 shots in one hole, the next hits low or high.
No change in the set up, just a non-conforming cartridge.
Folks like to blame the rifle for preferences due to poor results.
I've found there's a more reasonable answer....lack of uniformity in the cartridges.
This is an assembly line product we are discussing.
Multiple components being manufactured from a variety of materials,
then put together on a production line run by hourly employees.
Between mechanical tolerance slop and component variations,
lack of uniformity in results should be expected, not a surprise, right?

Add in statistical sampling to grade the lots, 400 shots to define a run of 16,000
sounds like there's plenty of room for problems to slip through what's being called quality control.

Click to expand...

This. I tested SK Biathlon the other day. 10 shots = SD 7. Next 10 shots from same box, same rifle, same conditions = SD 17.

grauhanen said:

The explanation offered above makes perfect sense for entry level match ammos (e.g. Eley Club and Target and SK Rifle Match and Standard +) and lesser quality fare where there may well be indifferent assembly of indifferent components by indifferent workers. The goal is quantity with some quality.

In a match ammo production run, components are sorted pre-production by their quality and in production loading machines are fine tuned is a matter of course. This care explains the very small sizes of many lots of match ammo. The goal is quality with some quantity.

To use the example provided, a random sample size of 400 out of 16,000 (2.5% of the total) gives a 95% level of confidence that the sample is reasonably representative of the rest of the population. That is a high level of confidence and it's time consuming to obtain. A shooting-only method of grading ammo would therefore be reasonably reliable in predicting the performance of the entire batch of ammo.

The problem remains that a shooting-only method of grading doesn't explain why some lots of Tenex or X-Act do indeed perform poorly -- not just on target but over the chronograph. If it has indeed been tested by shooting a sample, that shouldn't happen.

It seems doubtful that .22LR match ammo is graded by a shooting-only method. For entry level match ammos, variation within a lot is often so great as to make grading by shooting-only irrelevant. so.

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What I'm about to say may be completely incorrect so just take it as one shooters thoughts concerning Eley BB and 10X. Up until Covid and the ammo crunch hit I only lot tested and shot 10X. I found it easier to find a good lot of 10X than BB. Their seamed to be a difference in the two grades. They felt different when chambering in the same barrel. 10X was definitely more accurate. Fast forward to today. I can't tell any difference between the two grades. None! I don't pay the extra money for 10X based on their current grading system, but theirs's another side to this story. Some machines produce better ammo than others. Sponsored shooters and some top shooters world wide have access to this information. The general shooting public does not. We get the leftovers. Considering the current low production rates, the general shooting public probably never gets a shot at the really good stuff.

littlesister said:

What I'm about to say may be completely incorrect so just take it as one shooters thoughts concerning Eley BB and 10X. Up until Covid and the ammo crunch hit I only lot tested and shot 10X. I found it easier to find a good lot of 10X than BB. Their seamed to be a difference in the two grades. They felt different when chambering in the same barrel. 10X was definitely more accurate. Fast forward to today. I can't tell any difference between the two grades. None! I don't pay the extra money for 10X based on their current grading system, but theirs's another side to this story. Some machines produce better ammo than others. Sponsored shooters and some top shooters world wide have access to this information. The general shooting public does not. We get the leftovers. Considering the current low production rates, the general shooting public probably never gets a shot at the really good stuff.

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Are you still able to lot test before buying a decent quantity??

JimTN said:

Are you still able to lot test before buying a decent quantity??

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Yes. Killoughs still offers Eley in different lots. When they get a shipment in I have time to order, lot test and reorder, but you can't wait around or it will be gone.

Williwaw said:

If this were so I would expect that someone here would be able to give another example from another field where such an approach is used. I haven't been able to think of one. Anyone?

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Indeed. At the same time, if anyone reading this thread has experience in the mass production of something similar, they may be able to confirm your doubts. Anyone?

Of course in this case if there remains an absence of evidence from another field or the absence of confirmation of your doubts it isn't evidence one way or another, and it doesn't prove a thing.

The bottom line is that shooters don't know what grading methods are used because ammo makers won't reveal them. A hypothesis that can provide an explanation for what's regularly seen in practice might be more satisfactory than one that doesn't.

The idea that grading is by shooting-only methods doesn't explain why some lots that are ostensibly the best off the production line prove in practice that they aren't -- either over the chrony or on the target. It also fails to explain why lesser graded lots can in practice be much better than they should -- both over the chrony and on the target.

The idea that grading is by shooting-only methods doesn't explain why some lots that are ostensibly the best off the production line prove in practice that they aren't -- either over the chrony or on the target. It also fails to explain why lesser graded lots can in practice be much better than they should -- both over the chrony and on the target.

Sample size is based on statistics, right?
Statistics is mathematics based on the accumulation of data from previous experiences.
Sample sizes are based on the levels of confidence desired.
the higher the level of confidence, the larger the sample size needs to be.
Lot grading through statistical sampling does not guarantee the quality of entire batch.


Using the calculator linked above, note the differences in required sample size...

25,000 cartridges 80% +/- 5% level of confidence ...163 cartridges to test

25,000 cartridges 80% +/- 1% level of confidence...3520 cartridges to test

25,000 cartridges 95% +/- 5% level of confidence ...379 cartridges to test

25,000 cartridges 95% +/- 1% level of confidence...6939 cartridges to test

The reason for poor quality cartridges from factory tested/graded lots
is going to be due to the confidence level used to set the parameters.
Confidence level is not a guarantee, only a calculation based on results from previous testings.

To obtain a 95% level of confidence with 0% level of error, you have to shoot all 25,000 cartridges.

Statistics are a tool to assist in quality control, but if the sample size is too small, you can't trust the results.
That's why we get Tenex that spits strays and shows an ES of 73 fps. Testing is expensive.
Do the absolute minimum possible to maintain profits and still be able to claim the ammunition was graded at the factory.

That's why those batches tested at the factory run tunnels have such a variation in results.
If the grading at the factory was effective, X-Act or Tenex wouldn't show 23mm outside to outside
on those computer generated test results. That ain't rifle preference, that's poor quality cartridges.

Spend some time shooting across a chronograph with any brand or label of rimfire,
y'er gonna end up very skeptical with the labeling on those boxes of cartridges.
Hard to argue that the ammunition is high quality, when the chrony shows the variations in muzzle velocity