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Old 06-11-2021, 02:18 PM
rexxon123456
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How to grade this ammo



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I have been weighing some RWS R-50 ammo and most of it comes in at 52.8 or 52.9 grains. So I have some Eley club that shoots pretty good and is suppose to be about the same speed as R-50 and it is close to same impact as R-50. However as you can see from my photo its any where from 51.9 to 53.2 how would you attempt to separate this into lots
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Last edited by rexxon123456; 06-11-2021 at 02:58 PM.
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Old 06-11-2021, 03:12 PM
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Never much fun when they don't have the decency to distribute themselves into a single Sine Curve.
Appears that you have two peaks, centered on 52.4 grains and 52.7 grains....
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  #3  
Old 06-12-2021, 08:41 AM
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I wouldn't. After years of sorting by both rim thickness and weight I have found there is no effect on velocity or velocity spread. If you aren't affecting velocity, what are you improving?

Also after years of testing ammo for benchrest competition and chronographing every round, I have also found that the velocity on the box or as advertised bears little resemble to the actual velocity out of a rifle.

I also graphed the weight distribution of several different brands of .22LR ammo and know from experience as an engineer in the manufacture of semiconductors that general distributions do follow a bell shape curve. When they don't, it is because either not enough was measured or the distribution is skewed due to a manufacturing defect.

What sorting ammo by any method does is give the shooter something to do at night and gives them a good feeling.
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  #4  
Old 06-12-2021, 09:03 AM
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Just for giggles. This is the very first test I did many years ago when I first learned about flyers in benchrest shooting. This was a lot of Wolf Match Target still made by SK. I weighed an entire box and sorted the rounds into the same weight except in each group there was one round that was different in weight.



The round in red is the outlier in weight. In every group, the outlier is well within the group. But in group 1 and 5, there is a round that certainly can be called a flyer and they weigh exactly the same as the other 4 rounds. These are the reason I did this experiment in the first place.

Also note group # 10 which were picked at random and turned out to be the smallest group of all. If I wanted to be cute I would say, "Don't sort your rounds, you will get better groups". Group #11 was 5 rounds of a very good lot of Eley Match and the group size was actually larger that the "cheaper" unsorted group of the Wolf MT.

The main thing I learned out of this test was that sorting by weight didn't seem to improve where the rounds went on the target and using group size to evaluate a test like this is not the best way to make a decision. The group sizes went for .526 for the sorted to .240 for 5 rounds of unsorted. That is when I realized that you could only affect velocity by sorting and subsequent experiments proved it did noting to improve velocity spread.

Please before someone uses the old "You tested only match ammo" I will contend if you can't improve match ammo by sorting, what chance do you have to improve "cheap" ammo when the quality is effected by about a thousand other things that are very well controlled. Eley has found that even the humidity on the day the powder was made can have an effect on precision.

Last edited by MKnarr; 06-12-2021 at 09:06 AM.
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Old 06-12-2021, 09:16 AM
jaia
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MK is right...measuring cartridges is just another way to play with our toys.
Something to do in an effort to manipulate reality for the purpose of improving results, but doesn't.
It's possible you might pick up on a cartridge that was double loaded or not loaded with powder
but it won't actually fix the true causes of trajectory dispersion.
It makes ya' feel like y'er accomplishing something, but you ain't.
We are all limited by the quality of the cartridges as manufactured.
Sorting doesn't fix poor crimps, damaged bullets, irregular seating,
variations in powder/primer chemistry or amounts, tolerance shifts during assembly.

If you enjoy the process, knock y'erself out.
Just remember, been there, done that, 3 times, a brick each time.
Not worth the effort.

Lot testing at the factory run facilities is much more effective


PS: I just was reminded, even lot testing doesn't guarantee results.
One of the old coots at the diner table, pointed out that even at the Eley and Lapua test centers
y'er still basing y'er choice on a small sample from that particular lot number.
He has had an occasion where the results at the tunnel from two of the boxes tested were good.
Bought 3 cases of that lot number and found some of the ammo did not produce matching results.
Every purchase of rimfire ammo is a gamble...welcome to the assembly line lottery.

Last edited by jaia; 06-13-2021 at 02:42 PM.
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Old 06-12-2021, 11:01 AM
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I would weigh 20 cartridges together, divide by 20 to get an average. Take your average and keep any cartridge hits the average weight and keep any cartridge that is +.3gr or minus .3gr.

Save the culls for foulers or sighters.
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Old 06-12-2021, 02:03 PM
rexxon123456
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Thank you

Thanks for the reply's
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Old 06-12-2021, 03:30 PM
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22 LR is so diminutive you can't know if the weight difference is due to case, powder or bullet. Sorting by rim thickness has been more valuable than by weight. I tried sorting Remington bulk bullets and there was no improvement sorting.
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Old 06-13-2021, 09:02 AM
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Quote:
Originally Posted by rc. View Post
22 LR is so diminutive you can't know if the weight difference is due to case, powder or bullet. Sorting by rim thickness has been more valuable than by weight. I tried sorting Remington bulk bullets and there was no improvement sorting.
Been there done that. A box of Automatch.

As you can see, the major component of the weight distribution is the bullet while it is a fact that the primer even though it's weight is un measurable, it is a major part of the power.

Here is what happens when you measure rim thickness versus the velocity.

Note that seven rims are .032 and the velocity runs from 1036 to about 1067 FPS. BTW, that little r value at the bottom of the plot says they is virtually no correlation between the rim thickness and velocity and the slant of the next plot is in the different direction telling me that there is no correlation between rim thickness and velocity and I have the same kind of plots for weight versus velocity and they all tell the same story. No correlation.

BTW, that lot of Eley Match was a very good lot. As pointed out and I eventually found out, lot to lot testing is a lot more fruitful than anything you can do to improve ammo.

While I'm at it, I once did an experiment using an old firing pin spring in my Anschutz and a new one with a very good lot of Eley Team. Bottom line, velocity spread was reduced with the new spring to the 99% confidence level while group size was only reduced to only the 78% confidence level. Again, ignition is more important than the thickness of the rim. I now replace my firing pin spring once a year.

Last edited by MKnarr; 06-13-2021 at 09:11 AM.
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Old 06-13-2021, 06:26 PM
Lerrab
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rexxon, Put it all back into the 50 round box you got it out of. It is important that you do this one round at a time until you have filled the box. You can place it randomly into the box if you place them in ONE at a time. It will now be the best that it will ever be and you can choose from anywhere in the box and get the best results out of that particular box, It is a fool proof method!
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Old 06-13-2021, 07:48 PM
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Back when semi 17-HMR rifles began blowing up with ammo makers blamed the gun makers and visa versa I sought clues for prevention of my Rem blowing up and accuracy discrepancy clues. None for accuracy and my gun hasn't blown up so far. I did this with 10rds randomly picked from each of 30 or so various brands boxes of solids and hp ammo marking the boxes with powder or other variations. What I didn't do was measure the weight of priming nor test concentricity of the bullets nor crimp variances.
My conclusion was it was something to do to scratch an itch during a long winter and yielded nothing but more questions.

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  #12  
Old 06-14-2021, 02:06 PM
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Al, you are right about crimp strength. You never see a bullet turn in a match round like they do or don't in "cheaper" ammo. There is no doubt in my mind that crimp strength also has an effect on velocity variations.

Concentricity? Another variable. Some years ago the olympic coaches bought a concentricity gauge and found weeding out the ones that were out had no effect on the shooter's scores. Bill Calfee had a long post one time about that subject. He posed this challenge to benchrest shooters. Take a round that is non concentric put it in your rifle and then measure it again. No one took the challenge. His theory was that a round out when put in a tight chamber became concentric anyway.

But here is the flip side, the smith that put my Shilen barrel on my Anschutz used a reamer of his own design and the bullets do NOT engrave my lands. I have been shooting that rifle since 2006 with both Eley and Lapua. Yes I've had droppers with the Eley by not what I would call fliers with either ammo.

But by the same token, I am struggling with a 221 fireball with a Lilja barrel where I get 3 or 4 round in a .250 to .375 group at 100 yards and 1 or 2 rounds a half inch away from the group. After I bought a Sinclair concentricity gauge I found out that is the problem,. Some rounds were as much as .005 out and with .010 off the lands that leads to fliers.

Back to rimfire. If you aren't shooting a rifle with a tight chamber, is concentricity going to matter. It didn't seem to matter to the Olympic shooters but they are shooting high end ammo in rifles with tight chambers and can and have the experience to tell good ammo from bad at a 100 yards. I'm not now and never will be that good.

As an aside, I was recently asked o weigh some .22 caliber center fire bullets. BTW, I have found the rounds weighing exactly the same give no better groups than rounds that have wa wide spread. So no I do not weigh centerfire bullets before loading.

Jim

Last edited by MKnarr; 06-14-2021 at 02:11 PM.
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Old 06-14-2021, 11:38 PM
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Quote:
Originally Posted by ccwilder3 View Post
I would weigh 20 cartridges together, divide by 20 to get an average. Take your average and keep any cartridge hits the average weight and keep any cartridge that is +.3gr or minus .3gr.

Save the culls for foulers or sighters.

I'm fairly new to .22 50m BR.

If you are using your sighting shots to make final reticule adjustments wouldn't you use the best for those and not the culls?

Why would you use possible flyers?

My first short after sighting in might be more accurate if not based on a cull?

Last edited by ECC; 06-15-2021 at 03:07 AM.
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