Extruded primers

D

DrMLap

Inactive
I recently purchased a box of .303 Savage ammo from Graf & Sons. These have 150 gr jacketed RN bullets made by Hornady. I fired them in my son-in-law's Savage '98 which I had had thoroughly inspected by my gunsmith before firing anything in it. It shot just fine with no problems except one puzzling anomaly. Every case I ejected had a slightly extruded primer, about .016" to .020". And, oddly enough, the primers do not look flattened, as would be the case with a too powerful load. Indeed, the recoil of the weapon felt nominal. Other than sticking out a little, the fired primers looked normal.

It is my understanding that the headspace on a rimmed cartridge like the .303 Savage is determined by the gap for the rim measured from the face of the bolt. Thus, if the gap is too large or the rim is too thin, I could conceive of primers backing out. The rims on my cartridges measure about .058". The data I found says it should be .063". That doesn't seem to be sufficient to cause my problem. I have nothing with which I can measure the actual headspace of the rifle. I can only assume my gunsmith did that.

And in case someone should ask, yes, the Savage is chambered for .303 Savage and which is stamped on the gun.

So what could be causing my primers to extrude? Do I need to take the Savage back to the gunsmith? Do I need to avoid Hornady ammo in .303 Savage?

I think this mystery needs to be solved before I start reloading .303 Savage.
 
Photos?

Extrude like the primer backed out or the primer flowed into the hole where the firing pin came out of?
 
Should have included pictures.

And, to answer your question, primers are just backed out. Nothing going into the firing pin hole.
 

Attachments

  • 303_end_view.jpg
    303_end_view.jpg
    41.9 KB · Views: 113
  • 303_slant_view.jpg
    303_slant_view.jpg
    28.5 KB · Views: 95
  • 303_side_view.jpg
    303_side_view.jpg
    20.2 KB · Views: 88
It looks like your rifle has a little too much head space. If it were my problem, I'd fire form the cases to the chamber and neck size only...

Tony
 
A fairly common occurrence with the older Savage 99's. I'm surprised your "gunsmith" didn't warn you of this.
 
In all honesty, I should note that I mistakenly identified my rifle as a Savage 98. There is no Savage 98. It's a Savage 99.

Funny no one called me on that. :o
 
It looks like your rifle has a little too much head space. If it were my problem, I'd fire form the cases to the chamber and neck size only...
Click to expand...

You could still FL size but just not bump the shoulder back any further than necessary.
 
jmorris said:
You could still FL size but just not bump the shoulder back any further than necessary.
Click to expand...
Remember, these cartridges are rimmed. The shoulder does not determine headspace.

I've written an email to my gunsmith asking if he checked headspace when he gave my rifle a deep clean. I imagine he and I will be talking more about this.

Someone told me I should contact a different gunsmith. I might do that if I had a choice, but I don't. He's the closest gunsmith to me and he's 26 miles away. Well, there's another even closer, but he doesn't talk to his customers. You hand your gun to a clerk, tell him what you want done, and they call you when it's done. I want a gunsmith I can talk to face-to-face. Mine is the closest, maybe the only, gunsmith around who does that.
 
"In all honesty, I should note that I mistakenly identified my rifle as a Savage 98. There is no Savage 98. It's a Savage 99.

Funny no one called me on that. "

I did in a "tongue in cheek" sort of way.

"A fairly common occurrence with the older Savage 99's."
 
I’ve always thought primers that protruded from the pocket after firing were a sign of low pressure. Since that ammo is specifically (pardon the pun) aimed at “military surplus and vintage calibers”, could it be purposely under pressured by the manufacturer? Lawyers, liability and all that, you know.
 
Remember, these cartridges are rimmed. The shoulder does not determine headspace.
Click to expand...

Sure enough sorry, long day.

In any case you would just not lower the die as far.

How about a side by side photo of a fired case and one that hasn’t been fired?
 
Agree on excess chamber headspace. I don't know if it is endemic to Savage 99s, but that is what you have.

I do not think it is repairable within the value of the rifle.

I don't know if it is correctable with handloading methods. The primer is set back by the amount of the excess headspace which indicates the brass did not fully fireform to the chamber. If it had, you would have a flush primer and stretch marks on the brass. No reason not to try neck or partial sizing, I just don't know if it will make much difference.

I doubt the gunsmith "checked the headspace." As I said, I doubt he could have done anything about it anyhow.

I will see if Ken Waters has anything to say about the .303.
 
DrMLap,

In a gun with excess headspace, that primer protrusion is a classic sign of low pressure. The gun goes off and the primer's own pressure backs it out of the primer pocket, but the peak pressure never gets high enough to stretch the head back to reseat the primer, as happens at normal rifle pressures. It's easy to see this happening in the .303 Savage because the peak pressure standards were 35,000 CUP (SAAMI) or 39,000 psi (CIP), which Prvi will have referenced. They probably used a powder that was a bit slow for the application and got a rather lower pressure than that. It's hard to believe the original design was for such low pressures, as the cartridge was introduced to compete with the 30-30, but for older guns, it is often best to stay pretty conservative. If the design has trouble with 30-30 pressures, firing old cartridges that were once loaded hot enough to match the 30-30 might explain the headspace being long now.

You have several options. One already suggested is fireforming with a light load of pistol powder and some Cream of Wheat cereal filler. (This may still require the O-ring trick, below, to work properly).

Another option is to get some O-rings to slip over the cartridges and down against the rim that are not so thick (after stretching over the case) that you can't chamber them with the 0-rings in place. This tends to hold the head back against the bolt face during firing so the case shoulder blows forward instead of the primer pushing itself out of the case. A lot of 303 British rifle owners do this to get their shoulders to blow forward to fit the brass to loose chambers. If you have a lathe, you can turn a brass washer to take up the extra space exactly and give the rim a more solid base to fire the gun against.

Another approach is to shrug off the PPU load performance and reload the fired cases with something that gets closer to maximum pressure. My old Lyman #47 has 30 to 33 grains of IMR 3031 behind a 150-grain flat base jacketed soft point bullet. QuickLOAD suggests the pressure is getting into 30-30 range at the high end of that, so definitely start at the bottom and work up. A starting load of 23.5 to 25.9 grains of IMR 4198 looks like it would reach the same pressures, based on comparing ratios of the two in Hodgdon's 30-30 data. QuickLOAD agrees reasonably closely with this. This approach should stretch the cases, but it will be at the pressure ring and not by just blowing shoulders forward, so shorter case life will result.
 
I don't know if it is correctable with handloading methods. The primer is set back by the amount of the excess headspace which indicates the brass did not fully fireform to the chamber.
Click to expand...

A number of different methods to fireform cases, you don’t even have to use a bullet to do so.
 
I have a Savage 99 that once belonged to grampa. His is .303 Savage and had the same issue. His solution was to use a rubber o-ring common at a plumbing store. He would slide it to the rim. It took a wee tiny bit of extra force to close the lever. No more problems after that. I have not fired the rifle in 30 years. The ammo box has 10 left in it with the washers installed on them.
 
We were all concentrating on headspace..........
... which is known to drive people to distraction.
Click to expand...

Well the mis-understanding does, and then there are convoluted answers that bugger the mind.
 
You must log in or register to reply here.
Back
Top