Hypothetical question about old Swiss ammo

[DRNewcomb]

The Swiss are finally undertaking a clean-up of the Mitholz disaster site and there has been some occasional chatter about the possibility that some of the GP11 (7.5x55) ammo buried there might eventually become available on the surplus market. The big issue is that the age of the ammo (at least 74 years and short shelf life of the non-corrosive but mercuric Berdan primers used in Swiss ammo between 1911 and the 1950s.

While I've never had an personal experience with mercuric primers, authors such as Hatcher are clear that firing mercuric primers will embrittle the brass case so that it can't be reloaded. Hatcher also states that mercuric primers deteriorate rapidly when stored in less-than-ideal conditions. One would imagine that GP11 ammo stored in a cave for over 70 years would be almost all duds.

I suppose that such ammo could be broken down, deprimed, cleaned, reprimed and reassembled but it would seem to be a very labor-intensive undertaking and only worthwhile if the ammo were almost free.

I'd like to know if anyone here has had any actual experience with mercuric primers? They were not commonly used in the US for several reasons discussed by Hatcher: 1) they ruined brass for reloading, 2) short shelf life and 3) didn't work well in Boxer primers. The US military stuck with a corrosive, potassium chlorate primer (except for the M1 carbine and some experiments) until the 1950s.

Does a single firing with a mercuric primer actually ruin a brass case or is it a cumulative effect over many firings? What would be the chances that, otherwise undamaged ammo, buried in a mountain in Switzerland would actually go "bang" 70+ years later? Would just the slow deterioration of the primer over the space of 70+ years damage the brass?

Assuming you shoot 7.5x55, what would you do if you were given a case of 70+ year-old GP11 ammo?

 

[Dusty Stevens]

Is it berdan primed? Seems almost useless if so. And be assured we didnt spec our ammo to be reloading friendly. I bet that didnt even come up in a single meeting

 

[TylerFromMS]

I would shoot it. All the GP11 I have is berdan primed, however, so this may be one of those things that hasn’t really been tested.

 

[MislMan]

If purchasing to just shoot up cartridges then it may be OK. If looking to be able to reload I would pass on these since Berdan primed cartridges require special tooling just to punch out the primers. Berdan brass has 2 flash-holes versus the single center located flash-hole on Boxer brass.

 

[DRNewcomb]

If purchasing to just shoot up cartridges then it may be OK. If looking to be able to reload I would pass on these since Berdan primed cartridges require special tooling just to punch out the primers. Berdan brass has 2 flash-holes versus the single center located flash-hole on Boxer brass.

As it turns out, I'm set up to reload Berdan primed ammo and my stash includes two sizes of RWS Berdan primers. I really wouldn't have posed the question were this not the case.

 

[D-4297]

Since you can reload Berdan primered cases , then I'd shoot them and process them as normal . Maybe give them a second "wet" washing / soaking , to neutralize any residual chemical effects ... To those who are new to this , I have but one advisement for you . DO NOT TRY TO CONVERT BERDAN PRIMER CASES TO BOXER PRIMERS ! Doing so can be dangerous . The spacing of the two holes in a Berdan primer case places part of that hole OUTSIDE the diameter of a Boxer primer . You can ; and almost assuredly will get blow-back upon firing the round . I researched this for several months during our last shortage period , as I have three Mosin - Nagants that also use Berdan primered cases . There are You-tube videos out there , and some who claim they have a way to drill out the case to use a Boxer primer . Don't do it . If you aren't equipped to re-prime with Berdan primers as the OP is , you're risking damage to your rifle , and possible physical injury . Fifty-six dollars to replace a Mosin bolt-head that got burned up from flash blow-back tells me so .

 

[Mouse-Gunner]

About 50 years ago I inherited a quantity of US WW1 30-06 ammo. It had been reasonably well stored, nevertheless it showed evidence of a great deal of corrosion, especially around the necks. None of it was really safe to shoot, and I could break the bullets out of the necks by hand. Many of the bullets showed corrosion on their base. I saved some of the bullets and junked the powder and cases.

I’m glad I didn’t have any money in that ammo.

 

[JSH]

To my understanding the GP-11 was non corrosive mercuric primed. Later ammo was non corrosive non mercuric primes.
I think 1903 was the last year they had corrosive primers.
With global warming and such the stuff may well have been exposed to some what more humid and damp environment.
A quick look at the K31 sight should give you some solid answers to your questions.

I honestly really doubt you will see any of that ammo enter the
US of A.

 

[acloco]

I would like 10 or 20 K of the GP11.

SUPERB ammo.

 

[DRNewcomb]

To my understanding the GP-11 was non corrosive mercuric primed. Later ammo was non corrosive non mercuric primes.
I think 1903 was the last year they had corrosive primers.
.........

I honestly really doubt you will see any of that ammo enter the
US of A.

Like the US switch to non-corrosive, the Swiss switched to non-mercuric primers in the 1950s.

While I suspect that all the munitions recovered from Mitholz will be destroyed, the Swiss tend to sell surplus ammo outside Switzerland because the issuance of government supplied ammo is so tightly regulated there that unauthorized possession of GI ammo is almost prima facie evidence of misappropriation. Since any ammo from Mitholz will be way past its shelf life, it would not be issued to Swiss shooting clubs or used by the military but disposed of in some other way.

 

[nicholst55]

I recall reading tales of brass from mercuric primed ammo being reloaded - and suffering case failure - back in the day. These were old stories, even at the time. IIRC, the consensus was that if the ammo originally used mercuric primers, to scrap the brass. I've experienced way too much (old) foreign milsurp ammo being badly corroded inside, even when it appears serviceable on the outside to trust it very far. If this ammo becomes available, I would consider it a source of bullets, scrap brass, and fertilizer - but only if priced accordingly.

 

[Dusty Stevens]

Like the US switch to non-corrosive, the Swiss switched to non-mercuric primers in the 1950s.

While I suspect that all the munitions recovered from Mitholz will be destroyed, the Swiss tend to sell surplus ammo outside Switzerland because the issuance of government supplied ammo is so tightly regulated there that unauthorized possession of GI ammo is almost prima facie evidence of misappropriation. Since any ammo from Mitholz will be way past its shelf life, it would not be issued to Swiss shooting clubs or used by the military but disposed of in some other way.

So every adult there has a state issued military weapon but they cant have ammo for them?

 

[DRNewcomb]

So every adult there has a state issued military weapon but they cant have ammo for them?

They used to keep a sealed pack of GI ammo that they had to account for at drills. My understanding is that almost all of that was returned to the armories and is no longer kept at home*. GI ammo issued to shooting clubs must be fired at the club and is strictly accounted for. If you have a permit to acquire a gun you can buy and keep as much commercial ammo for that gun as you can afford. Handloading is also allowed but not a big cost savings. The strict controls are on military-issue ammo.

*The exception, as I understand it, being those personnel who are responsible for security during a mobilization.

 

[Lee in Texas]

No way would I fire that. I don’t want a dud getting a bullet stuck halfway down my barrel.

 

[RegionRat]

I will spew a few thoughts and take a guess that isn't worth the time it took to type this out...

Based on the sophistication of the Swiss Match crowds, I would venture a guess that if any of this ever gets put on the market, it would be after some serious sampling shows it is still fit for purpose before hand.

They may not have as many lawyers per capita as we do here in The States, but they still have them...

 

[piie]

I would think that the known effect of the mercury in the primers causing issues with the brass would immediately disqualify it as an option for you to reload in any event - even if you are equipped to deal with the berdan primers - you will have suspect brass after firing?