Flattened primers.....

[itgoesboom]

Went out to the range this last weekend, and brought two batches of reloads for my .30-06. For the record, I have just started reloading a few weeks ago, and had already shot 2 batches with no issues.

Batch #1 was H4350, Sierra 175 matchking, WLR primers and virgin Winchester brass. I had seen two sets of data on this, some starting at 52gr, some at 55gr, some maxed out at 57.5, some at 59. So I started at 52 and went to 59, 1gr increments up to 56gr, .5gr increments after that.

Batch #2 was IMR 4064, Sierra 165 Gamekings, WLR primers and once fired Federal brass. Starting load was 49gr, max was 52.5.

Batch #2 had no issues at all.

Batch #1 I had flattened primers, on all rounds fired. From starting, (actually, below starting according to Hodgdon) all the way through max loadings.

But, no cratering, no hard extraction, no punctured primers, no bulged cases, no ejector marks, no case head flowing, etc.

Only flattened primers.

I have asked on a couple other forums, and I got some good answers, but I want to see if there are anymore ideas.

On the other forums, it was speculated that it is a headspace issue, that the winchester brass is at one end of the tolerance spectrum, and my chamber at the other, and the stacking tolerances have caused me to get false pressure signs. Sounds logical to me.

One thing I also noticed is that my once fired brass has a much sharper shoulder angle than the virgin brass.

I should also mention, I never had any issues with factory loads that I have fired through this rifle either. Also, the cases from batch #1 did not stretch excessivly, they are actually really close to their trim to length.

Any thoughts?

Thanks in advance.

I.G.B.

 

[Winger Ed.]

I wonder if the new brass was a little on the small side of the specs. for it's calibre

Try one of the brand new brass & a once fired that you've re-sized:

Prime them, then 'shoot' one of each.
You'll probably need to hold the muzzle on a loose pile of rags or a folded up towel to let the primer's discharge build a little bit of pressure. It'll sound like a .22LR, and push out a gas charge about like a pellet rifle.

Now look and see if the primer has backed out more on one than the other. Unless you do this with a neck sized brass- any primed brass will have the primer back out to one degree or another.


When the primer fires in the otherwise empty case, it scoots out (if it can) so that the distance from the shoulder to the rear of the primer will be the chamber length/headspace.


In firing a loaded round:
If the primer scoots out farther than 'normal' due to a short shouldered brass/loose chamber/excesive headspace, when the powder goes off and pushes the brass back against the bolt, then finishes fire forming it--- the primer can bulge a little before its slamed back all the way into it's pocket.

If that's what's happening, you'll get a false high pressure sign of the flattened primer.

That would be my guess as to why your once fired ammo/brass did fine, and you got a (false) high pressure sign from the new brass.
The real test is to re-load the new brass now that it too is once fired, and see if it does it again
(which it probably won't).

.

 

[Powderman]

I could be wrong here, but I think that your choice of powder might contribute to it.

What type of rifle are you shooting?

 

[USSR]

itgoesboom,

Without any other signs of high pressure, I wouldn't worry about it. Probably just the difference between the Winchester and Federal brass.

Don

 

[hagar]

59 grains of H4350 with a 175 Sierra is a dangerous load, I would not go over 56 grains. You don't say what kind of rifle, if it is an M1 Garand, H4350 is not a suitable powder. If you are only seeing flat primers, with no soot leaking or shiny spots on the case head, and your loads are within specs, don't worry too much.

 

[USSR]

59 grains of H4350 with a 175 Sierra is a dangerous load, I would not go over 56 grains.

Not at all. It's a 48,700 CUP load that is well below SAMMI specs with the Winchester brass that is being used.

Don

 

[jmorris]

Go buy a box of factory winchester shoot a few and see what the primers/case look like.

 

[itgoesboom]

Rifle is a Weatherby Vanguard sporter in .30-06. Load data was taken directly off of Hodgdon's new data website, data.hodgdon.com.

They list 59gr of 4350 as max load when using 175SMK and Win. brass and WLR primers. So the exact components that I am using, so I know I am in spec.

Thanks everyone for chiming in with your ideas.

I did discover one more thing last night when I was measuring the casings. When I put a primed Federal casing on my desk, head down, and a Winchester casing on my desk, head down, there was a difference.

The Federal casing sat flat on the head on the flat surface. The primer was seated deep enough not affect how the casing sat on the flat surface.

The Winchester casing did not sit perfectly flat on the flat surface. The primer was not seated deep enough to not affect how the casing sat on the flat surface.

I checked 3 primed Winchester casings, the only 3 I have primed, and all three were the same. I checked 1/2 dozen of the Federal, and they all sat flat.

I then checked the depth of the primer pockets of both types, which I had checked a few days ago. Federal casings pockets were few thousandths deeper than the winchester pockets.

I wonder if this is part of the issue, that the primers just aren't seated quite deep enough?

Anyone think that might be part of the issue here?

Thanks again.

 

[chris allen]

flatten primers

Different lots of brass (made by the same manufactuer) have differing internal volumes .So what works with one lot may not be appropriate in another . That is why the loading manuals always tell you to work your way up to max. loads.

 

[itgoesboom]

Chris,

Starting load also had the flattened primers.

I.G.B.

 

[Smokey Joe]

Flattened primers

Itgoesboom--FWIW, I have exactly the same thing occurring in my .300 WSM. When I fire virgin brass, I get flattened primers. Firing the same cases again, in the same rifle, after neck-sizing, trimming-to-length, and reloading with the same load, I do NOT get flattened primers.

My conclusion is same as Winger Ed's--When the virgin brass is fired, it is shorter than the chamber, and, following Newton's Laws of Motion, the "body at rest" which is easiest to move is the primer. Then the bullet moves, but also the case stretches to fill the chamber, mashing the pushed-out primer.

Since that is my ONLY "overpressure sign" and since it goes away with fired cases, I'm OK with ignoring it. But I watch carefully for any further signs.

 

[USSR]

The Winchester casing did not sit perfectly flat on the flat surface. The primer was not seated deep enough to not affect how the casing sat on the flat surface.

itgoesboom,

Would suggest you invest in a primer pocket uniformer.

Don

 

[Ol` Joe]

Quote:
The Winchester casing did not sit perfectly flat on the flat surface. The primer was not seated deep enough to not affect how the casing sat on the flat surface.

itgoesboom,

Would suggest you invest in a primer pocket uniformer.

I agree somewhat, but 1st would double check to see if the primers are seated to the bottom of the pockets. You may just be seating them shallow.

 

[itgoesboom]

Don,

Got one, but I think I am going to let Winchester take care of this, just so I don't screw it up.

Ol' Joe,

They are seated fully, I seated them as fully as possible, the same as on the Federal cases.

Measuring the depth though, the Winchester cases have shallower primer pockets.

I.G.B.

 

[chris allen]

primers

You may have a rifle that does not have any lead or throat before the rifling starts. Or you may have a rifle that has excessive headspace .It need to be looked at by some one .

on rare occassion I have run into a rifle that is severley fouled , and pressures are eratict

 

[itgoesboom]

Chris,

Unlikely, since this rifle has had no issue with other handloads or with factory loads. I have a couple hundred rounds through the rifle with no issue, until I used the Winchester brass.

At this point, it looks like the primer pocket is the issue, since it is not allowing the primers to seat properly.

Winchester has issued a call-tag, and is going to examine the unfired and fired brass, and replace it for me.

I.G.B.

 

[The Bushmaster]

Try this if you will...change to H4831SC in Winchester cases and a CCI 200 primer. Oh say around 57 to 58 grains of H4831SC. See if that doesn't change things...I use 58 to 59 grains of H4831SC under a 165 grain HPBT Sierra Game King with great results from a Browning A-Bolt .30-06...And no flattened primers.

 

[Smokey Joe]

Smartest thing to do!

IGB--Yr going to send the brass back to Winchester? Smart maneuver. If there IS a manufacturing defect, the least they'll do will be to send you replacements which are not faulty. (Which would cure the problem.)
And Win will be grateful, because they need to know what kinds of defects are getting out from their plant, so's to correct them.

Companies are usually very helpful in correcting manufacturing errors, with a certain few exceptions.

If it's NOT a manufacturing defect, then you'll know to look elsewhere for the answer.

 

[pilot teacher]

All primers are not created equal. Some cups are harder than others, some are softer. Try different brands to compare. Usually primers do flatten to some degree. But if yoiu see cratering around the firing dent it may be a sign of high pressure due to primer cup metal bunching up around the firing pin. Try different primer brands.