Ammo Crapshoot

[justin amateur]

RT....y'er having way too much fun poking fun at my journey into tedium.

Keep it up and you get to do the next batch....ooooh....that was too harsh a reply.

I wouldn't make anyone attempt this, unless they enjoy succumbing to their OCD.

 

[RTH1800]

On a serious note I like what you do. It confirms what I see casually at times and refutes some other non scientific observations of mine.
Thanks for your efforts and more so for sharing.

 

[justin amateur]

Okay RT...another week of tedium accomplished.
Tenex, 50 cartridges disassembled and weighed.
Data entered into the spread sheet, here's the results...

Eley Tenex

 

[mrt949]

Nice work .What did you do for a living before you retired .

 

[justin amateur]

Raised kids....


And the comparisons....

...............CARTRIDGE...........................................................................BULLET..........POWDER.....PRIMER.............BRASS

 

[BillOH]

Justin, I've heard it said that there are 2 bad rounds in every box of 50. Can you determine which ones were in this box?

Next test is to reassemble the rounds and shoot them.

Thanks for doing all the testing.

 

[justin amateur]

No idea which would do what Bill.
Something I did notice....after emptying all the powder from the cartridges
the thing I saw that surprised me was the amount of primer flakes/chunks visible in the powder.
Those flakes in the powder are going to affect the powder/primer calculations...how much? No clue.
I had read rough handling could knock primer loose from the brass,
even tested to see what effect a drop would have on a box of 22lr,
this was the first time I simply pulled cartridges apart and emptied the entire box into a single container.
All those chunks indicate there was a good chance of fail to fire due to missing primer.

 

[mrt949]

Justin A TEACHER No wonder you have O.C.D .

 

[RTH1800]

You deserve an award for all you share here. Thank you.

 

[justin amateur]

I've added another data column....charge...the total amount of combustible (primer + powder) in each cartridge.

That last column shows the charge available in each cartridge, average amount, deviation and spread.
Deviation for the CCI is about a third larger, spread is almost 40% of the average.
Tenex spread is about 16% of the average. I'm thinking that's where those mv variations originate.

 

[justin amateur]

You liked that extra column mrt?

Spread sheets are mighty handy for data mining.

Sorted by cartridge weight in grains, heavy to light
Compare total cartridge weight to charge weight for that cartridge.
Is there a pattern?

CCI SV

TOTAL...CHARGE
51.23....1.42
51.23....1.4
51.14....1.42
51.1.....1.26
51.1.....1.43
51.1.....1.48
51.08....1.24
51.08....1.54
51.06....1.32
51.06....1.41
51.04....1.35
51.04....1.42
51.02....1.39
51.01....1.4
50.99....1.52
50.98....1.47
50.98....1.29
50.94....1.24
50.93....1.6
50.92....1.23
50.92....1.09
50.92....1.39
50.92....1.27
50.92....1.49
50.92....1.24
50.92....1.53
50.92....1.24
50.91....1.39
50.9.....1.39
50.9.....1.24
50.88.....1.57
50.87....1.45
50.85....1.27
50.84....1.24
50.82....1.41
50.81....1.24
50.8....1.38
50.8....1.26
50.79....1.46
50.78....1.24
50.78....1.39
50.78....1.06
50.77....1.24
50.77....1.55
50.76....1.08
50.76....1.39
50.61....1.38
50.61....1.23
50.46....1.39
50.46....1.26
1.3518 AVERAGE CCI SV
0.1254655006 STANDARD DEVIATION
0.54 EXTREME SPREAD


So.....do you see any pattern that supports sorting cartridges by weight to improve mv spread?


With that cartridge weight side by side with charge (primer and powder) weight,
it's real easy to see there's something that just doesn't work with sorting by weight.
Like those charge amounts being larger in some of the lighter cartridge weights
or lighter in some of the heavier cartridge weights.

 

[justin amateur]

One last sorting of the CCISV and the Tenex data

By total cartridge weight from heavy to light
last column is the percentage variation of the powder/primer charge compared to average.
Values are positive or negative (plus or minus relative to average powder weight of all the cartridges)

Any patterns there?

CCI SV

Tenex

CCI SV has the largest variation in powder/primer charge.
I don't see a pattern there.
Those charge percentages vary up and down with no visible relationship to total cartridge weight.
One of the heaviest cartridges has the lowest charge.
One of the lighter cartridges has the heaviest charge.
Weight sorting does not produce any useful result.

 

[Parkerized]

We appreciate the fact you were blessed/cursed with OCD. So much good info debunking the status quo.
If you have another attack you can't control ( hope not for your sake) and feel the need to get greasy fingers Lapua Center-X would be a great contender to the Eley and the CCI.
Thanks again for doing all of this.

 

[*rim-star*]

It took awhile for me to figure it out.

1) Get used to inspecting each cartridge prior to chambering.
Look for defects. Any kind of dent or ding indicates problems at the factory.
If the nose is beat up, so is the heel. If the heel is damaged, you get strays.
Any asymmetry causes wobbles, pitch, yaw....not good for accuracy

2) Feeding from a magazine into the chamber can damage the drive bands.
Top round drags the rim across the bottom round leaving a groove.
Damage the drive bands you get strays. If the mag is slightly off line with the chamber
the drive bands will be shaved by the edge of the breech, causing strays.

3) Get used to shooting across a ballistic chronograph and listening to the muzzle pop.
You can correlate mv differences to the sounds caused by weak or hot rounds.
Even in the frequency of the vibrations transmitted from the stock to your cheek bone.
You can hear the mv differences and see where they impact high or low.

4) Don't think rimfire cartridges are all identical. Not from the same lot number,
not from the same brick, not even the same box. It's mass produced rimfire.
Components and assembly tolerances vary moment by moment on the production line.
You can't shoot the same cartridge twice. That's why results vary.

10/22 Shooters should really look at this, they are notorious for damaging bullets in the magazine.

 

[mrt949]

I Have a 77/22 lr That i made a single shot loader .
After i paid $20.00 from Ruger single shot .
That you must load each time good for training not for shooting .
I had to put a peace if ZIP TIE.
In the front so the nose of the bullet wouldn't fall down inside of the mag.

 

[justin amateur]

Did you hear the squeal of brakes and a thump-thump?
Yep, I was thrown under the bus again.

"Hey...these cartridges are showing all sorts of vertical.
Take 'em apart and figure out why."

Why me? I know, no good deed goes unpunished.

So I was handed a box of 40 grain CCI Maxi Mag TMJ 22wmr.
Woe is me. Tedium-r-us.

Did learn something though in the first 10.
That 40 grain bullet, as labeled, only weighs about 38.5 grains.
Powder is running just over 6 grains and primer is 0.2 to 0.5 grains.
That's the same primer amount as the CCI SV.
It would have to be, wouldn't it?
Manual priming method, punch plate and squeegee.

 

[FuhQ]

Every barrel has what it likes. The tough thing/fun is figuring out which one.

I noticed this as well. I never thought much about .22's being as sensitive as centerfires, but they really are. The old 20" .920 Butler Creek SSM stainless steel match bull barrel I had in my 10/22 for 19 of the last 20 years that I've owned it, it has shot just about everything pretty decently, especially bulk pack stuff. It really loves the old Federal 525 pack 36 grain copper-plated HP's. Those were the bread & butter for that thing. If it was inside of 100 yards, it better beware, because it would shoot 1/2-3/4 MOA regularly. Still got that barrel, and plan on getting it threaded down the road for another 10/22 build.

But after swapping it out for a threaded barrel last December (after purchasing my Dead Air Mask HD), the new Valquartsen carbon fiber barrel I put on it, does not really care for the bulk-pack Federal, and shoots 2" groups at 100 yards with it, and it's any man's guess at 200 yards where it's gonna land. Luckily I found the CCI Standard Velocity 1070 FPS ammo, and it loves that stuff. It shoots 1" to 1.25" 10-shot groups at 100 with that stuff. And my new CA Ranger 22 shoots 0.3xx" 3-shot groups at 100, and put down a 1.200" 3-shot group at 200 with the CCI SV. I got really lucky that both of them like the same ammo. So now I just buy it in bulk when I can.

 

[justin amateur]

....every barrel has what it likes

True. It likes tight muzzle velocities and cartridges assembled with a minimum of defects.
Without those two items to start with, results will reek unless used at close range, 30 yards or less.
I've found certain barrels do better with a specific range of muzzle velocities, plus or minus 15 fps.
Outside that range vertical spread shows up. Inside that mv range it looks to fit barrel harmonics.
Too bad it has nothing to do with brand, only how well the cartridges were made.
When the cartridge shows signs of rough handling on the assembly line, irregular seating,
asymmetry and audibly hot and weak rounds, no rifle can magically fix those problems
and produce predictable trajectories.

 

[RTH1800]

^^^^^
This is exactly correct.

 

[FuhQ]

True. It likes tight muzzle velocities and cartridges assembled with a minimum of defects.
Without those two items to start with, results will reek unless used at close range, 30 yards or less.
I've found certain barrels do better with a specific range of muzzle velocities, plus or minus 15 fps.
Outside that range vertical spread shows up. Inside that mv range it looks to fit barrel harmonics.
Too bad it has nothing to do with brand, only how well the cartridges were made.
When the cartridge shows signs of rough handling on the assembly line, irregular seating,
asymmetry and audibly hot and weak rounds, no rifle can magically fix those problems
and produce predictable trajectories.

I think that's why my 2 carbon fiber barrels like the subsonic (1070 FPS) ammo, and aren't really consistent with the 1200+ FPS ammo.

 

[justin amateur]

I used to think that also Q.
Then I had some results at 200 yards surprise me.
Eley Force hi-v and Eley Contact subsonic, produced same sized 50 shot groups.
That's not supposed to happen. But it did.
1080 fps 22lr and 1250 fps 22lr from the same rifle, 20 minutes apart at 200 yards.
Why did that happen? ES less than 45 fps for both...minimal visible defects.
Cartridge quality determines the consistency of the trajectories, when the wind cooperates.

 

[justin amateur]

Another week's worth of evenings down the drain.
Weighing, recording and data entry....so much fun. Not.

Again, bullet and charge being the two biggest variations.
Is there a correlation between total cartridge weight and powder/primer?

 

[grauhanen]

Minimal visible defects.

The heel of the bullet is unseen but very important with regard to performance. It may be described as a relatively delicate part of the bullet.

After taking apart .22LR ammo, is it possible to determine when the bullet heels are damaged or inconsistent in dimensions? How does such heel variation differ in a box of ammo? What percentage of rounds have heel issues?

 

[RTH1800]

@justin amateur pulls down every round and inspects bullet heal prior to shooting his famous 100 shot groups. He does this while measuring and correcting powder charges and primer compound weight. Then he re assembles the components in a uniform manor. Finishes up with a custom taper crimp die.
Justin and I are anchors. He anchors the top end of the rimfire precision world.
I anchor the bottom end.
Our net effect is to provide balance to the equation. Please see last nights “wallet groups.”
3 shots at 100 yards 5 shots at 200 yards. Prone, tight sling,

to check POI and data.

 

[justin amateur]

I anchor the top end of the asking annoying questions, RT.

I kept reading posts about sorting by weight and kept asking the question: "What exactly are you weighing?"
The answer was always "powder variations"
Even when I pointed out there were gonna be differences in the other components,
the comment was ignored because we all know that manufacturing rimfire ammo is a high precision process.
No way could the primer, brass or bullet vary more than a hundredth of a grain, eh? It's gonna all be on the powder.


G....all you have to do is look at the bullet, right out of the box, to have a pretty good idea how the heel is gonna be.
If the nose shows dents, dings and scratches, it tells us that the bullets were handled poorly during manufacture and assembly.
When watching the CCI factory tour video, I cringe with every drop, dump, rattle, bump and shake shown.
I can see where those dents and dings come from....it's on every surface of the bullet, including the heel.
I don't need to pull the bullet to know the heel has been hammered during production.

 

[justin amateur]

How do I know those heels are damaged?
Screen snaps from the CCI vid...

I always tumble my bullets in a cement mixer before seating them, right?
It's guaranteed to ensure pristine uniformity of all the surfaces of each and every bullet.
Nose, drive bands, heels are all going to be evenly beat to snot, right?
Then I'm going to dump them a good 20 or thirty inches free fall to impact on each other
thereby allowing gravity to help with the damage.

Then I'll tumble them some more in the plating tank.
That way I can add a few more dents and beat up the plating too.

And for another bit of abuse I'll dump them again,
because who doesn't expect predictable accuracy from deliberately damaged bullets, eh?

Yep, that there is some quality ammunition.
Those heels are absolutely pristine/undamaged, eh?

All you have to do is use Mark I eyeball.
If the nose is beat to snot fresh out of the box...that's bulk ammo.
Expect strays....those heels are beat to snot too.

 

[RTH1800]

CCI folks are going to be looking for you.

 

[justin amateur]

At least CCI doesn't try to hide the reasons for all those strays.
That factory tour video explains so many of the problems inherent with American made rimfire ammo.

 

[RTH1800]

It suits the market it’s intended for.
I have been selling huge quantities Eley ammo for 6 months. Idiots at gun shows ask, do you have any Remington or CCI?

 

[justin amateur]

No argument RT.
It's bulk ammunition intended for hunting and plinking.
It's actually capable of better results than I am, when shooting offhand with rifle or pistol.
Why waste competition quality cartridges, when I lack the skills needed?

 

[straightshooter1]

Why waste competition quality cartridges, when I lack the skills needed?

. . . to reduce one's margin of error?

Maybe an issue when varmint hunting?

 

[justin amateur]

Straight...my margin of error offhand is beyond anything better ammo could fix.

Seriously, at 25 yards a 24 inch x 24 inch backer shows holes out to it's limits.
and I'm aiming at a 1 inch dot on center. Safest place to be is on that dot.

 

[RTH1800]

Ouch!

 

[justin amateur]

Offhand, most anything I chase in the woods is safe RT.

But give me a tree to brace on, fence post, my shooting stick, bipod prone, I can get it done.

 

[grauhanen]

G....all you have to do is look at the bullet, right out of the box, to have a pretty good idea how the heel is gonna be.
If the nose shows dents, dings and scratches, it tells us that the bullets were handled poorly during manufacture and assembly.
When watching the CCI factory tour video, I cringe with every drop, dump, rattle, bump and shake shown.
I can see where those dents and dings come from....it's on every surface of the bullet, including the heel.
I don't need to pull the bullet to know the heel has been hammered during production.

I wasn't referring to what's obvious, that is ammo with visible defects. There's a lot of ammo used by shooters, such as SK varieties, most of which doesn't have those visible defects that characterize bulk ammos and CCI products.

For example, if someone were to examine SK Rifle Match ammo without a loupe, he wouldn't see many visible defects. This ammo nevertheless often can behave like it's got something wrong with it that isn't explained by the chronograph.

 

[justin amateur]

Understood, G.
With those cartridges made without those visible problems,
as you already know, the only way to find out is to shoot them.
No other method will identify those cartridges.
Not weight sorting, not rim thickness, not length.
As has been posted so many times,
lot testing is how you find the best ammunition.

 

[grauhanen]

Indeed.

My question was simple: "After taking apart .22LR ammo, is it possible to determine when the bullet heels are damaged or inconsistent in dimensions?" In other words, after removing the bullet, can damage be determined to have been there before cartridge disassembly? Or does cartridge disassembly damage the bullet?

 

[justin amateur]

Had to check the bags of components, G.
All three types of extracted bullets show damage at the heel.
Deformation caused by the pliers used to grip and extract.
No way to determine if any damage was there prior to removal.
You would need to cut the brass off below the crimp
without igniting the primer or powder,
then look at the heel inside the remaining brass.
That'll be rather difficult. EOD tech wanna give this one a try?


Also checked fired 22lr bullets recovered from my poly-fil trap.
Heels shows irregularities, unsure if from production
or if due to deceleration in the polyester fibers in the trap.

50 at 200

don't mind me but I think I will drill a hole all the way thru the bullet to see if it will whistle going down range. thinking out of the box or out of my mind. thank for another great idea I want to try the 50 at 200 this summer when there is no wind layder

www.rimfirecentral.com

 

[6.5SH]

Should start a new type of match. I propose naming it the "Reverse Krappen Schuetzen".
Use the best ammo you want but offhand at 25 yards. Then the crappiest ammo you have (must be agreed upon as being sufficiently poor quality) supported prone at 100 yards.

Scoring could be some sort of aggregate between them, perhaps both target score and group divisions.

 

[grauhanen]

Thanks, justin.

I'm thinking that perhaps bullet heel irregularities may at least partly explain bullet POI that is not predicted by MV. Recently I shot a variety of lots of ammo in as nearly ideal conditions as is possible. Among less expensive varieties of ammo I observed a higher frequency of rounds going where their MV didn't predict than I saw with good lots of Lapua. That is to say, more SK rounds did unexpected or strange things than Lapua, such as slower MVs resulting in a higher POI and vise versa as well as more instances of greater horizontal spread.

When rounds that don't appear to be damaged, nicked, or irregular behave in ways that MV doesn't predict, something else is happening.

An alternative explanation might be that SK ammo may have higher incidences of center of gravity issues than Lapua. Of course, bullet heel irregularities may contribute to or cause center of gravity problems.