Factory Lot Testing

[justin amateur]

Ever wonder how 22lr was tested at the factory, to determine labeling?
Say Lapua for instance...what metric decides if it's X-Act, Midas+ or CenterX?
All three are manufactured using the same components on the same assembly line.

It's going to be based on statistical sampling, can't shoot the entire run.
If ya' did there'd be none to sell. So how would you go about grading a batch?

Been giving this some thought and reading about statistics and Acceptable Quality Level.

 

[Fuckmikebush]

Justin this is the million dollar question. My other question is how many rounds are being shot out of the test barrels before cleaning? What barrels do they use and what actions are these barrels attached to? Back when I first started eley was top dog and you could find really good lots of the blue box wich was the same as red box just down graded. You can also find really really bad lots of red box or lapua xact. Eley used to have a lot analyzer but it didn't help much in weeding out good or bad lots. They did away with it about 3 years ago. Definitely a interesting topic of what's an acceptable amount of testing to determine what lots belong in what box.

 

[justin amateur]

I contacted Lapua and asked....


By what procedure does Lapua determine if a lot of 22lr coming off the assembly line
is X-act, Midas+ or CenterX. The question came up in an online discussion.
A previous article related that it's accomplished by shooting random samples,
from each batch, from a number of barreled actions and checking muzzle velocities
for standard deviation and extreme spread.
Could you describe the process and the numbers that define the grading?

Hi Justin,
You're on the right track, but I'm afraid I can't divulge the exact nature of the testing
in terms of standards that you're after. Proprietary, and strictly in-house info there.
I will say that every run of ammo, either Lapua or S-K, is accuracy tested in a series of five 10-shot groups,
as well as a 50-shot composite. The SD and ES are measured and are required to fall within a strict set of parameters,
but ultimately, it's accuracy that makes the final determination. Those that pass this initial testing
and show the best promise, are then retested. There are repeats of this same testing in several different test rifles,
in essence winnowing down the field. If it passes that testing at a certain level of accuracy,
it becomes X-Act, or is downgraded to Midas+ or Center-X, depending on where the measurements fall.
Testing of rimfires is problematic, as the ammunition tends to be so rifle specific and,
for lack of a better term, temperamental. In doing such testing at one of our Service Centers
in either Germany, Finland or Mesa, AZ, I've seen countless examples of Center-X or Midas+ outshooting X-Act,
regardless of how they tested during acceptance testing.
In those cases, count yourself fortunate that your rifle prefers the less expensive stuff.
The bottom line is, you simply can't rate match grade rimfire ammo from best to worst
strictly by the showing it makes in the test rifles. It's a start,
but you ultimately HAVE to test the lot in your particular rifle to know.
I hope this answers your, at least as far as I can answer it
without violating the specifically proprietary methods and specs.
If there's anything more we can do to be of service,
please don't hesitate to let us know. As always, we'll be glad to help.

Sincerely,
Kevin Thomas
Sales Manager
Nammo Commerical Ammunition

Reading between the lines, there's some corporate obfuscation in the reply.
Blaming results on rifle preference instead of methods used in batch testing.
When CenterX is outshooting X-Act, there might just be a glitch in the factory grading process.

 

[b6graham]

so basically they sell X-Act and Midas+ at a premium price and it may or may not shoot better than CX and likely shoots the same

and this is why i shoot CX

 

[justin amateur]

I hear ya' B6.

I have to think that results on target determines labeling.
The real questions are....how big are the sample sizes?
What are the acceptable defect rates allowed?
What are the aggregate group sizes that make the final decision as to X-Act, Midas+, CenterX?

Those are what are being hidden as "proprietary information".
Not method of testing, that's relatively easy to figure out.

Need an indoor 50 yard/meter facility, environmentally controlled, air filtration system,
4 barreled recievers in fixtures mounted to a heavy reinforced base,
with a digital target system and ballistic chronograph recording data.

 

[b6graham]

i haven't sent a gun to Lapua yet so i dont have data on hand as far as what a standard spread is between multiple lots

but take a sample of 8 or so lots of say CX that go through someones gun at the testing center (or the testing center gun)
1-2 of those lots are probably X-Act quality (what the owner would buy)
2-3 of them are probably M+ quality
3-5 of them are probably CX quality

it just happens to be that lot of CX gets X-Act or M+ quality groups and/or velocity spreads

 

[justin amateur]

Suppose you end up with a batch of 14,000 cartridges from one run.
How many do you test? What dimension does the sample group aggregate need to fit?
What number per 100 tested is allowed to exceed the established parameters?
Can't test the whole batch, there'd be none to sell.
Can't test too few, end up with faulty data and incorrect labeling....or is that the problem?

 

[grauhanen]

When a production run is made the result is varying quantities of the three varieties of Lapua rimfire ammo -- X-Act, Midas +, and Center X. It would seem reasonable to believe that quantities of X-Act are less than M+ and that of the three varieities CX is produced in the greatest quantities.

Lots are determined by certain adjustments or changes to the loading machinery (what these may be are not publicly revealed), anticipated changes in lots or batches of components (e.g. lead for bullets, casings), and probably other factors rarely discussed outside of match ammo production plants.

Is it reasonable to say that the lots of ammo that emerge at the end of a production run are randomly either X-Act, Midas +, or Center X? That is to say, is it to be expected that until they are somehow evaluated no one at Schönebeck, where the ammo is manufactured, has any idea whatsoever whether a lot might be any one of the three varieties that get made?

What if the three varieties -- X-Act, Midas +, and Center X -- don't come off the production line in a random order?

 

[grauhanen]

As speculation, perhaps it wouldn't be surprising if the technicians and managers at Schönebeck have a very good idea of what to expect to result from a production run. They know the machinery and the components and expected changes in their quality standards. Perhaps they know where in the run the "best" ammo ought to be made and likewise where the other two varieties can be expected to be produced.

Actual testing may be done to confirm what is expected.

Of course X-Act doesn't always perform like the best and some lots of CX outperform some lots of both X-Act and M+. This suggests that having an idea of what variety each lot ought to be would not be a foolproof method of identifying which lots should be X-Act, which should be Midas +, and which should be Center X. At the same time, however, it offers an explaination as to why X-Act is not always universally better than Midas and Midas always better than CX.

 

[justin amateur]

Hey G, from queries sent to Eley and Lapua, the replies indicate
the better 22lr cartridges are manufactured, then tested, in order
to determine the quality of the that particular batch before boxing and labeling.
Each individual run/batch has a portion of the cartridges sent through the test barrels
to verify whether or not the sample meets the necessary criteria.
The testing likely is based on standard statistical sampling,
used in most manufacturing processes to meet the desired level of quality.
Testing sample sizes are based on the level of confidence needed in the test results.
Confidence levels can be inserted into an equation, and the sample size needed to test
is calculated based on the number of items in the batch.
So do you want an 80% level of confidence that the testing is accurate? 90? 95? 99%?
The higher the level of confidence you want, the larger the sample size required.
The more cartridges tested, the greater the expense, where do you balance it?
That would be the proprietary information being hidden.
Anyone can fire ammunition and record results. Not difficult.
Computer tracking transfers data to a spreadsheet and the numbers crunched.
Do the resulting numbers say X-Act, Midas+ or CenterX? Tenex, Match or Team?

For a metric, based on my 200 yard 50 shot groups, 4 inches of spread is about as good as I get.
At 100 yards that'd be 1.3 inches of spread and at 50 yards expect 0.4 inches center to center.
Add 0.2 inches and you get 0.6 inches outside to outside for 50 shots.
That works out to about 16 mm of spread, outside to outside, for the best cartridges.

So the best cartridges would test out with a 16 mm aggregate spread at 50 yards/meters.
Call it 18 mm for second best and 20 mm of spread for third best. Maybe.
This is where the acceptable defect rate sneaks in.
How many strays or fliers are allowed per hundred?
That's where quality control gets sticky. You know due to the method of manufacture
and components used, there's going to be some defects.
How many and how bad, is the worry.

Acceptable Quality Level

The Acceptable Quality Level is a statistical tool to inspect a particular sample size for a given lot and set maximum number of acceptable defects. In order words, it is the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling. The AQL has been...

www.whatissixsigma.net

 

[grauhanen]

Hey G, from queries sent to Eley and Lapua, the replies indicate
the better 22lr cartridges are manufactured, then tested, in order
to determine the quality of the that particular batch before boxing and labeling.

justin, for reasons of public confidence in their products, it seems impossible that Eley or Lapua would openly admit to any process other than testing alone for determining whether a lot is, respectively, Tenex/Match/Team or X-Act/Midas/Center X. In other words, could they say anything else than "Yes, we test every lot or batch before deciding on how to package it."?

I speculate that there's more to deciding what variety (i.e. Tenex /Match/ Team? or X-Act/Midas/ CX?) than a scenario in which an ammo production run makes a number of lots of ammo and the ammo maker is reduced to saying "OK, now let's test these lots and find out what variety each is going to be."

I also speculate that testing is done to confirm what the ammo makers can already reasonably be expected to believe. That would explain why when the Eley Lot Analyser was available, it showed testing of 200 rounds through four test barrels. The confidence levels that can be reached on the basis of testing 200 rounds of a lot of that could be tens of thousands can't be very high.

In a lot of ammo that is six cases (30,000 rounds) in quantity, which is not atypical for Tenex, the number of rounds that must be tested to have a 95% confidence level is more than 200. The question becomes, when actual testing is performed, is it feasible or practical to test more than 200 rounds from any lot of any variety of Eley or Lapua?

The following may not be accurate, but as an illustrative exercise, using an online sample size calculator, in a sample of 30,000, a 95% confidence level requires a test of 380. A test of 200 gives a confidence level near 85%. (If these figures are not accurate or relevant here, I welcome corrective advice.)

 

[justin amateur]

Morning G, I've been running numbers with this calculator to determine sample size.

Sample Size Calculator

Input level of confidence desired and batch amount, provides number of items to be tested.
Change the margin of error allowed, and watch the numbers shift.

If you have a batch of 14,000 cartridges, you'd need to test 374 for a 95% (+- 5%) level of confidence.
For 99% rating it goes up to 636....that's some extensive time spent in the test facility.

If you test 400 cartridges, you need multiple barreled recievers.
Send 25 at a time through each barrel to minimize temperature changes.
Moving barrel to barrel as you work through the test sample.
Batch testing is not going to be cheap.

With a batch of 14,000 if only 200 are tested, that about an 85% level of confidence.
Meaning if you tested 100 times, 85 would produce the same results.
The other 15 times, not so much. Explains why there's so much variations in cartridge quality,
even with factory testing.


Now after reading all the procedures and numbers of cartridges needing to be tested
that is done at the factory, that leaves me thinking about the factory run test centers.
If you are going to purchase 10,000 cartridges, how big a sample do you test to decide
if you're going to buy the two cases? Only 40? That has me thinking it's too small a sample.
Only 40 to determine if the quality is worth the cost? Is that enough?
Calculator says 162 need to be tested for an 80% level of confidence.

 

[JG26_Irish]

This is an interesting question and I wish I had more visibility of the answers. I always figured that when the machines were just put back in service after an overhaul, maintenance, cleaning cycle, they would run some ammo and the first cartridges went into SK or Eley Club, Wulf etc, once the run had stabilized, then the product flow was ear marked for X-Act or Tennex. After that the flow was tagged for Midas+ or Eley Match, and lastly the flow was marked to become CX or Eley Team. As the Machines approach time for the next overhaul/Maint cycle the run would once again be boxed as SK or Wolf ammo. Then a small sample of each run is tested to figure the mean velocity and confirm that it goes in the box it was planned for.

In addition, I have never had Tennex shoot better than Eley Black. I always figured it was cause the Tennex is not flying off the shelves of the suppliers as fast due to price limiting the demand. Thus it spends longer periods out in the warehouse/garage/storage and may sometimes be exposed to extremes of temperature which may affect its quality post production.

 

[acudaowner]

it all sucks , either buy it or make your own oooh you can't spin your own primer compound in a 22 lr case well

 

[brianf]

The real cray BR guys in England (maybe here as well) only buy ammo from a particular employee and particular production equipment.

 

[justin amateur]

The process of testing isn't difficult to figure out.
Place cartridge in hard mounted barrel/receiver.
Pull trigger. Record muzzle velocity and point of impact. Repeat.
The only real questions are how many are tested per batch,
what amount of spread defines the label
and what is the acceptable number of defects per 100?
If I'm going to use the test facilities, and spend some hefty bucks
on a multi case purchase, I sure want to obtain the best return for my money.
Until now I thought 40 was a worthwhile sample size,
based on previous samples being tested at the factory.
Now I think it needs to be a much more substantial amount
so as to make the purchase less of a gamble.

I've purchased bricks of RWS R50, Tenex, Eley Match, Midas+ and CenterX
and had some that were as good as I hoped, others that disappointed.
It appears the testing/grading process isn't as effective as I think it should be.

 

[Boxerglocker]

A while back I was speaking to some very avid BR shooters one of whom had direct ties to the one of the prominent 22LR manufacturers and asked this same question. The simple explanation given to me was all production is done in rotating runs and that the upper tiers such as Midas Plus, Eley Tenex , RWS R50 are all manufacturered first in lots with all components of the same exact individual manufactured lot. So same lot of bullets, same lot primed brass, same lots of powder is one lot. Once a machine runs out of one of the three components and can no longer be replenished with the same lot, it is now reclassified as another lot of the same tier or the next lower grade tier depending on the supply of components available. Lesser grade runs are based on the same components but tracking the individual components lots isn't as critical.

 

[chevy_man]

None of it really matters.

What does matter is real world results in your particular rifle.

Some lots of x-act shoot bug holes in 1 rifle and crap in another. Same goes for every other gun and ammo combo.



You can't get around lot testing. There's too many variables that we can't accurately quantify to make any predictions worth betting on. It's so much simpler to just shoot and let the results tell you what's good.

Generally they're going to charge more for the stuff that graded better in their test guns.

Now, I regularly beat on a guy running a rimx. He has a $7k into his setup, and won't buy $12/box ammo. He loses matches and blames everything but the ammo.
Don't be that guy.

 

[grauhanen]

The process of testing isn't difficult to figure out.
Place cartridge in hard mounted barrel/receiver.
Pull trigger. Record muzzle velocity and point of impact. Repeat.
The only real questions are how many are tested per batch,
what amount of spread defines the label
and what is the acceptable number of defects per 100?
If I'm going to use the test facilities, and spend some hefty bucks
on a multi case purchase, I sure want to obtain the best return for my money.


I've purchased bricks of RWS R50, Tenex, Eley Match, Midas+ and CenterX
and had some that were as good as I hoped, others that disappointed.
It appears the testing/grading process isn't as effective as I think it should be.

Only if the factory actually tests each and every lot in order to determine whether it's X-Act, Midas, or CX will it matter if there is an ES standard that defines the label. (As for an "acceptable number of defects per 100" -- there should be no physical defects with individual rounds of match ammo. Such things may be a frequent characteristic of bulk ammos but not of much more costly match ammos.)

If all lots are indeed tested to see if they meet certain ES requirements, then it might be taken for granted that across good barrels all lots of X-Act will generally have smaller spreads than Midas, which in turn will have smaller spreads than Center X. The premise that all lots are tested is undermined by the fact that in many barrels some lots of CX outperform some lots of both M+ and X-Act.

I understand that spreads may vary from one barrel to the next, and that ES is not necessarily a guarantee of performance, but the fact that some lots of CX can have smaller spreads than M+ or X-Act across many barrels begs the question of whether all lots are tested -- or at least tested for extreme spread.

Regarding getting your money's worth at a testing facility, while lots that quickly show poor performance need little testing, it seems reasonable that a customer should be able to request further testing of a potentially good lot of ammo. It's when several lots show similar but not exceptional performance that wickets can get sticky.

 

[justin amateur]

I follow y'er logic G.
With the grading process hidden, no way to know how the results are applied
or if testing each individual batch actually takes place. Is lot grading/labeling applied science,
or a marketing ploy to justify a higher cost per cartridge? If not all lots are effectively tested,
then results are not going to be what the consumer is looking for. If testing by the shooter
is a single box, then the shooter is basing an opinion of the rifle's "likes" on a very limited sample.
If the box tested was from the low end of the quality scale, "my rifle doesn't like "R50".
If the box is from the higher quality portion of the lot "my rifle loves RWS products".
Small sample sizes tested can lead to incorrect conclusions.
Poor testing procedures can lead to unhappy consumers and poor sales.

 

[Mr. Wolf]

I am not a statistician, but have used quite a bit of it in my work.
Much of the earlier works in statistics seem to derive from gambling, alcohol, or both.
William Sealy published his paper under the pseudonym “Student’s” t-test while working for Guinness Brewery.
He had to design a way to assess the quality of the product without the brewmeisters getting sloshed and not being able to discern the quality of the stout.
For your reading pleasure: https://en.wikipedia.org/wiki/Student's_t-test

I’ve been to the Lapua testing facility in Marengo, OH and had my CZ 457 tested in their indoor range.
If memory serves, the best 10 shot group at 50M was approx 11mm outer edge and 23mm outer edge at 100M.
We shot 16 lots and the first one turned out to be the best. The top 4 lots were reshot with similar results and the lot I purchased had a nice circular pattern compared to others that had some diagonal or vertical stringing.
I don’t recall any measurement of speed in my print outs, but by placing a 3 in front of the first 2 numbers in the Center X lot number will give you the factory measured speed in M/s.

Some form of the method I observed is what is probably used for testing to separate out Midas vs Xact vs Center X. Also makes good sense that they use the same batch of powder, case, and bullets for optimal consistency until they mix components as they run out of some and becomes mixed batches.

I also think that they might have a way of testing for bullet concentricity or damages through X-ray or automated video imaging to decrease the sample size.

Finally, economics likely also comes into play. In semiconductor manufacturing, it is not uncommon for chips to be binned to meet what the manufactures think is the demand for each type then do less number of tests for the remaining. In the chip world, some SKUs and bin numbers are famous for overclocking and can surpass even the best/most expensive top tier chips. Sadly, they sometimes nerf these chips with lasers etching to lower core counts and/or cache memory to meet lower tier specs.

In the dark art of rimfire accuracy, is it any wonder that a certain barrel with a lower grade ammo, when tested properly can outshoot the more expensive stuff? In my opinion, the Lapua and Eley testing centers are the best use of time and money… Now on to tuning those buggers for an even tighter group (maddening and fun).

Recent outdoor competition shoot at 50 yds, 7-10 MPH tail winds, 37 F, 1st shot high and left, scope adjust, then 4 more into this beaut. That tuner might be doing something…

YMMV, happy shooting

 

[obx22]

Hmmm, this makes me wonder about the barreled actions used in these ammo production/sorting tests, as well as the cleaning-prep procedures....

 

[justin amateur]

I can offer some information on the barrels.
They're match barrels ordered direct from a custom barrel maker.
Bought multiples at a time so as to be able to replace when accuracy falls off.
As the throat and leade wear due to the number of rounds fired each week,
it reaches a point that it affects the spread. The factory replaces the barrels.
Depending on barrel material, replacement can occur at as little as 50,000
up to 120,000 rounds sent. I contacted Lapua, Eley and RWS to find out.

Michele Makucevich <[email protected]>


ELEY monitors barrel performance through the use of control batches.
When performance using these control batches starts to diminish
we will change the barrel to ensure accuracy is maintained.
The barrel wear is very much dependant on the type, quality and cleaning and maintenance
it has received. Some will last for 75,000 rounds, others in excess of 110,000 rounds.
Best regards,
Michele Makucevich
Key Account Manager

Frank Green from Bartlein Barrels adds a few comments on barrel life...

We have made and make ammunition test barrels for 22LR. We made a batch of barrels for a customer that went overseas several years ago. This was for Norma and the testing was for a European Olympic team. What I was told that after testing our barrels tied for 1st place in the accuracy try outs for the team. They only went with the European maker at the time because of the import/costs etc... About 3-4 years ago another well known rifle maker bought twenty 22rf barrels from us for testing. Two of those rifles went to Eley. Which led to a order for 300. Now they place an order every year. They said there were barrels that would shoot as good, ....but none shot better than ours. I don't know when they pull the barrels for barrel life over in Europe at the test facilities like RWS/Eley/Lapua etc.... I do know this....over here in the States barrel life is approx. 80k plus rounds before/when they pull them. The AMU pulls their barrels around 40-50k rounds if I remember correctly. Really depends on the accuracy required and what you're using them for. The other thing that I find interesting on test barrels for 22Rf that we've had requests for where we did the chamber work... it's either the standard Saami sporting chamber or the Saami match chamber. The Saami match chamber to me is really tight. I wouldn't run it on any of my guns. What and when they use one over the other....my guess is as good as yours.

Wachtler Thomas RUAG <[email protected]>

Mar 15, 2021, 1:53 AM (1 day ago)

Dear Sir,



We assume that a .22l.r. barrel approx. 50,000 rounds.



With best Regards

Thomas





Mit freundlichem Gruß

Thomas Wachtler

Customer Service BU Hunting & Sport


RUAG Ammotec GmbH
Kronacher Straße 63
90765 Fürth/Germany

Telefon: +49 911 7930-202
E-Mail: [email protected]

Phil Hoham from Capstone Precision Group <[email protected]>


Straight from the factory.

" Our standard rifle in the factory is a Walther KK500. Here we notice precision loss after 150.000 up to 180.000 rounds.
The barrel of such a rifle is made of carbon steel. Some other European manufacturers do it in the same way like Anschütz or Feinwerkbau.
More and more stainless steel barrels come up in rifles made by Bleiker or Grünig+Elmiger.
Those rifles have a high quality and precision but the barrels are very soft and less resistant.
So you can use the rifles with good precision only for approximately 50.000 rounds.
In US you will have other manufacturers but the situation will be the same.

But the question is what a shooter understands if he speaks about a decreasing precision.
I guess there is only a hand full of shooters that could detect the effect in her daily exercises.
We use very clever fixing systems (and those are from time to time in discussion because of the precision)
and electronic measurement devices to detect the growing target circle. Very less people can do that in the clubs or at home.
A usual club shooter will never notice that his old rifle shoots worse after 20 years compared to the days as he bought it.
Top level shooters need a number of new barrels or rifles in her shooters life. They practice much more and have higher requirements. "

 

[obx22]

I can offer some information on the barrels.
They're match barrels ordered direct from a custom barrel maker.
Bought multiples at a time so as to be able to replace when accuracy falls off.
As the throat and leade wear due to the number of rounds fired each week,
it reaches a point that it affects the spread. The factory replaces the barrels.
Depending on barrel material, replacement can occur at as little as 50,000
up to 120,000 rounds sent. I contacted Lapua, Eley and RWS to find out.

Awesome info!

 

[rick137]

I will beat this drum one more time. My hypothesis is the support system has a significant effect on accuracy. What ammunition is most accurate in one support system, say the one used in testing, may not be the most accurate in another, bipod and rear bag on the ground. What I hope is that the magnitude of the accuracies for different ammunition may change with the support system, the relative accuracies do not.

@justin amateur has repeatedly demonstrated that shit ammo produces shit results. And exterior defects are a good indication of shit, i.e. low accuracy, ammo.

Has anyone put their green eye shades and done a @justin amateur examination for exterior ammunition defects in Center-X, Midas+, and X-Act That is something which only requires a magnifying glass. In a case, what would be the percentage of exterior defects in the stated three types of ammunition? Exterior defects are not the only factor in accuracy since an exterior defect may only have a small effect on accuracy but they would presumably have a correlation to the selection process used by the manufacturer.

 

[grauhanen]

Has anyone put their green eye shades and done a @justin amateur examination for exterior ammunition defects in Center-X, Midas+, and X-Act That is something which only requires a magnifying glass. In a case, what would be the percentage of exterior defects in the stated three types of ammunition? Exterior defects are not the only factor in accuracy since an exterior defect may only have a small effect on accuracy but they would presumably have a correlation to the selection process used by the manufacturer.

Upper tier match ammo can be expected to generally be free of obvious exterior defects. More important are issues that can't be seen unless the round is disassembled and destroyed.

The heel of the .22LR bullet is vital to accuracy and it remains beyond inspection unless the round is not used.

In his book, Ammunition Making, which has some excellent information on .22 rimfire in general and a chapter on .22LR match ammo, made the following observation. (The people he refers to are Franklin W. Mann, author of the 1909 classic The Bullet's Flight from Powder to Target, and Edwards "Pete" Brown, author and shooter.)



Steve Boelter, longtime shooter, former president of Anschutz North America, and author of Rifleman's Guide to Rimfire Ammunition, emphsized in an interview the importance of the .22LR bullet heel was to accuracy.

"If the heel is not perfectly symmetrical around, it will push harre'sder on one side than the other -- if there's a dent or a ding... There's less resistnace on one side. If the bullet sarts and the heel isn't perfectly formed it gets pushed off-center, now your bullet isn't symmetrical anymore, and your center of gravity is off, and you go back to the wobble. Anytime the bullet enters the rifling not perfectly straight, it negatively affects accuracy."
See Boelter's interview in Michael R. Shea, Rimfire Revolution, pages 243 - 244.

 

[rick137]

Upper tier match ammo can be expected to generally be free of obvious exterior defects. More important are issues that can't be seen unless the round is disassembled and destroyed.

The heel of the .22LR bullet is vital to accuracy and it remains beyond inspection unless the round is not used.

In his book, Ammunition Making, which has some excellent information on .22 rimfire in general and a chapter on .22LR match ammo, made the following observation. (The people he refers to are Franklin W. Mann, author of the 1909 classic The Bullet's Flight from Powder to Target, and Edwards "Pete" Brown, author and shooter.)



Steve Boelter, longtime shooter, former president of Anschutz North America, and author of Rifleman's Guide to Rimfire Ammunition, emphsized in an interview the importance of the .22LR bullet heel was to accuracy.

"If the heel is not perfectly symmetrical around, it will push harre'sder on one side than the other -- if there's a dent or a ding... There's less resistnace on one side. If the bullet sarts and the heel isn't perfectly formed it gets pushed off-center, now your bullet isn't symmetrical anymore, and your center of gravity is off, and you go back to the wobble. Anytime the bullet enters the rifling not perfectly straight, it negatively affects accuracy."
See Boelter's interview in Michael R. Shea, Rimfire Revolution, pages 243 - 244.

@grauhanen:

Thanks for the intel. Another example of the Rimfire Uncertainty Principle. You cannot both know if the bullet has a defect and shoot it. Or another reason why shooting rimfire ammunition is Rimfire Roulette. Only statistically determinate as in quantum physics.

Rick

 

[Emerson0311]

The profit impact cannot be ignored. If putting ammunition in a different box means you get to charge double $$ for it, with the same production cost, that is the driving force behind factory ammo testing/grading. Lapua/Eley do not exist to further the desires of Rimfire geeks. A bit of statistical analysis to determine how much truly consistent ammunition is required to maintain the value of the brand, and Bob is your uncle.

 

[justin amateur]

Ahhhh....Schrödinger's Rimfire Cartridge theorem....I understand.

The cartridge is both perfect, and imperfect, simultaneously, until the box is opened.
At that moment, the observer, simply by making an observation, affects the quantum hinge point,
after which the cartridge becomes either worthy of the price paid, or unworthy.

 

[obx22]

Ahhhh....Schrödinger's Rimfire Cartridge theorem....I understand.

The cartridge is both perfect, and imperfect, simultaneously, until the box is opened.
At which point the observer, simply by making an observation,
affects the quantum hinge point, after which the cartridge becomes either worthy of the price paid, or unworthy.

That post was worth the price of admission
I swear if it were a meme I’d steal it!

 

[rick137]

One final factor. The cartridge may be "defect free" from the factory but will it be "defect free" after loading?

There is a reason for shooting single shot rigs or repeaters with a sled. For my money the ultimate long range precision rimfire rig is single shot.