Last week some one on this forum mentioned the US military switch over from corosive primers to mercury primers.This bothered me but I thought my memory bank was getting screwed up. Since than I was given a 1000 Western No.7 IMPROVED Non- Mercuric, Non-Corrosive Primers circa late 50s. All these years it was believed that mercuric primers and corosive primers were synonymous. Is this right or wrong? roger

Roger,

I think the corrosive part is referring to potassium sulfate that used to be used in primers. It formed a corrosive that attacked barrels.

The mercury was used for a while in primers and I think it supposedly made the case brittle. IIRC the mercury was not responsible for barrel erosion.

I could very likely recall all of this quite well if my high school science teacher didn't let us play with so much mercury......

Jim

Mercuric primers were replaced with chlorate primers in the very late 1800's. Chlorate primers are/were non-mercuric, but are corrosive. Non corrosive lead-styphnate priming compounds came along sometime in the 20's or 30's.

Not so! The "corrosive" agent in corrosively primed ammunition was chlorate of potash which has a high affinity for water, not mercury. That's why hot, soapy water works well for cleaning after firing corrosive ammo like the commonly available military surplus stuff -it cuts the salt left behind where a petrochemical solvent might not. Remember the old G.I. bore cleaner in the small bottles? It was made for cleaning corrosive salts as was the original Hoppe's.
Mercuric primers (fulminate of mercury) were not a problem in the days of black powder where the fouling generated by it absorbed most of the metallic mercury, however, they became an issue with smokeless powders. Mercury attacks brass rendering cases useless for reloading. With few exceptions, mercuric primers have been a thing of the past since the 1930's. The last mercuric primer I'm aware of was the old Winchester 8 1/2G, and they became history in 1960. The element of choice in primers is lead styphnate (trinitroresorcinate), and has been for over 75 years.

I was under the impression that mercuty primers disappeared early in the metallic cartridge days back in the late 1800s but i could be wrong.

The chlorate primers- potassium chlorate or perchlorate based -left potassium chloride salt in the barrel that acted a lot like common table salt and causes the rusting. The actual material in the corrisive primers is similar to the tip of a strike anywhere match; in a pinch match tips have been substituted for primer material.

The military stuck with the corrosive primers for a long time because of the long shelf life. I've got FN 9mm and .45 acp non-corrosive cartridges from the early 50s that are 100% duds where corrosive stuff from the 30s and 40s is still 100% good.

The lead based primers of more recent years are now being replaced by non-lead materials but I haven't read much on that yet.

Thanks all for the education.I take it than that the mercury does not corrode steel but does corrode brass;"--to weaken or destroy gradually--" (Webster) roger

mercury does not corrode the brass, it amalgamates with it; it dissolves in it.

funny you should ask about mercury and steel, I have never heard that asked. good question.

here's what hatcher (or tenny, IIRC) had to say: fulminate of mercury was the original priming comound. it worked well. black powder was the propellant. later, when smokeless came out, it left much less residue, and the brass became weak. turns out the copious BP residue diluted the primer residue and protected the brass. huh. AFAIK mercuric primers disappeared with BP as the standard propellant.

so the came the chlorate primers which are among the best, but they leave salts that will cause corrosion. they were so superior to non-corrosive primers that the commies used them up to at least the 80s, and chromed their barrels and chambers to protect againt the corrosion.

these days, non-corrosive primers, which are styphnate based, have all but taken over. they appeared in the 1920s.

Here is the story ;

Just for the record Winchester and Western brand sold Mercuric Primers in the teens and 20's - 30's for reloading smokeless powder ammo . I've still got little cardboard boxes with Wood Carriers in which the primers are on their sides rather than in pucks .

Corrosive primers contain mercury fulminate, which is strike sensitive, and an amalgam of potassium chlorate as an oxidizing agent, and rosin as a binding agent and fuel. The mercury fulminate gets the reaction going when the primer is struck by the firing pin, and gets hammered against the “anvilâ€. The potassium chlorate and rosin begin reacting violently to create a jet of hot, burning gas which then ignites the main powder charge. The problem with this reaction is that one of the byproducts is potassium chloride, which ends up on metal surfaces and attracts moisture, which quickly starts the corrosion process .

Modern non-corrosive primers use lead syphnate, which doesn’t leave moisture attracting salts. The lead syphnate is bound up with ground glass as a frictionator, tetracene as a sensitizer, along with an oxidizing compound, typically barium nitrate, and a fuel source, such as antimony sulfide.

Non-corrosive primers are more prone to degradation than corrosive primers, in large part because tetracene makes the primer a lot more heat sensitive.

There have been a lot of advancements in primer technology lately, particularly with non-toxic primers.

I won’t pretend to be an expert on any of these . These are just facts and not mine at that .

Shoot Straight Know Your Target . ...

quote:

Originally posted by Dr.K:
Here is the story ;

Nice presentatation Dr. K. roger

As early as 1930, corrosive primers were found to produce better accuracy than the non-corrosive. Some 7.62x51 Match ammunition with special mercuric corrosive primers was still being made as late as 1958. I have a full box of empty primed 30-06 Match cases made by Western in the 1960s that is clearly marked as having corrosive primers.

As far as I know, corrosive primers are no longer used for match ammunition in the USA. I suppose the little gain in accuracy was more than offset by damage to match rifles when not properly cleaned after firing the corrosive ammunition.

Ray

Well, I guess we all have read about the adoption of fulminate of mercury in "pill" form for igniting powder charges, by a certain clergyman of Great Britain (Forsyth). That occurred right about the turn of the 18th to the 19th Cengury (1800 +/- a few years).

- Later, those "pills" were made separately carryable & appliable, by being enclosed first in copper, later in brass, caps. Hence the "percussion" era.

- Some were also available in strips of paper tape, very similar to the caps for a "cap gun" of our youth. The tape primers were used in certain Civil War firearms, for instance, in concert with paper "cartridges" such as had been previously used in muzzle loaders. Some were also placed in "wafers" similar to the paper caps, but not in rolls. Those rifles actually "threw" the wafer between the hammer and the nipple, between the start of the fall of the hammer and its impact with the nipple. Quite a feat of timing, that!

- Then, as the brass cartridge case was developed and popularized, what we know as "corrosive primers" were also developed, but the early ones were pretty much both "mercuric" and "corrosive", though of course they were not advertised as being corrosive to firearms.

- In the 1880's through mid-1930s era, all sorts of problems ensued, both with brass and with barrels, but though the shooters of some countries knew why, Americans on the whole did not. (Some did, but most had "theories" which were either untrue or only partially true).

One such very long-lived "wrong" theory, for instance held that it was the smokeless powder gas that was corrosive, not the primer residue, and that it worked its evils by getting into the "pores" of the steel barrels where it could not be removed by cleaning unless such cleaning was done regularly every day for a week, then every week for a month, and then once a month forever. Guess why so many bore cleaners were called "Nitro Powder Solvent", including one very famous good-smelling one....?

But eventually, we began to figure it out. To avoid the problems with barrels, some primers became non-corrosive, but remained mercuric. They of course, still destroyed the brass for handloading in short order, if used with smokeless powders. AS Dr.K pointed out, with black powders they were diluted enough in the residue to not be the same problem.

Others became non-mercuric, but remained corrosive. A primary example was the FA-70 primer produced by the military and sold to handloaders through the NRA & DCM. It was retained by the military primarily because it had very good shelf-life under adverse storage conditions, which was of primary importance in cartridges which MUST go "bang" in time of war. The military retained the use of that primer in some 30-06 cartridges at some arsenals as late as 1958.

In Europe, primers used in manufacturing commercial sporting cartridges generally became non-corrosive & non-mercuric at least 10-15 years prior to when that occcured in the United States.

Remington brought out the first large-scale use of non-corrosive, non-mercuric primers (Kleen-bore) in the U,S. in the late mid-to-late 1920's and they did it by buying the formula from the Germans, NOT by developing it themselves.

A bit after Remington started capturing the market with its new primers, Winchester also converted to mainly non-corrosive primers, though some of their's remained mercuric.

(Though of no importance to all of this, I still have boxes of 1,000s of all those types and manufactures of primers in my shop as reference materials.)

Anyway, until the mid-1960's, some of Winchester's "Western" labelled match ammo in both .30-06 and .300 H&H was STILL mercuric (though non-corrosive). Why? Because it had good shelf-life, and was generally considered more consistent in performance than the non-corrosive/non-mercuric primers.

Mercuric primers did not totally disappear until the mid-1960's in the U.S. sporting and target ammo.

Canuck

A great summary.

Ray

Top is Western empty primed Match cases. Bottom is the back of a box of 7.62x51 AMU Match ammunition.

Interesting that Western simply called them "corrosive" while AMU called them "special mercuric, corrosive".

Ray

Ray -

That "corrosive" ammo is a good find, and thanks for showing us all the pictures of it.

Somewhere I have some boxes of the .300 H&H which is the old red, gold, and blue "Western" boxed civilian stuff shooters used at Camp Perry in the late 30's and 40's. I am almost certain it was labelled "Non-Corrosive, Mercuric", but now I am going to have to find it and check it out again.

If it was also corrosive, you have taught me something new, for which I thank you, and I will have to edit my post to show the correction.

Sure wish I could learn how to post pictures here; I'd try to take and post photos of a bunch of the different old boxes of primers with their labels, in some sort of order which would show the evolution of them all.

Best wishes,

AC

BTW, do you by any chance write occasionally for Wolfe? You have a style, and area of interest, which seem to match that of one of my favorite all-time writers on ammo.....

AC

I wouldn't read too much into the way they label boxes. Some of the big companies have a way of mixing terms and the marketing guys who probably design the labels may not know the difference between corrosive, mecuric, etc. I'm like you, I always thought they are two very different mixtures.

I did write a few articles for Wolfe but it was many years ago, when Neal Knox was still alive. I have written articles on cartridges recently, published mostly in collecting Journals, but some of them have been re-published in Gun Week and places like that. I'm also a Forum junkie and you'll find my stuff all over cyberspace.

I think I know who you mean at Wolfe. I send him an e-mail every once in a while nit-picking his stuff and I'm sure he can't wait to hear from me.

Let us know if you find that 300 H&H box. I'd like to know what it says.

I'll bet Roger never thought his post would turn out to be a history on primers. But it is/was a very good question Roger.

Ray

When Smokless powder replaced black powder the formulation had to be changed, (less mercury, more chlorate and the addition (eventually) of aluminum) because the older mercuric primers wouldn't reliably ignite smokless propellants.

Then very soon after the mercury was eliminated entirely for chlorate(oxidizer) aluminum (fuel)
after it was discovered that the mercury caused embrittlement of the cartridge cases making them dangerous to reload.


Nobody really noticed the corrosive residue from the primers with black powder because it was simply "lost in the flood" of powder residue.

Yes the mechanism of combination between the mercury and the brass cartridge case was via "amalgamation" but "dissolve" is pretty far afield from reality... there is only a tiny ammount of mercury in a primer (it's like the idea that a drop of water can dissolve an entire salt lick) and while it is liberated from the combustion of the primer, much of it is swept down the bore with the propellant gases and very little is left in the cartridge case, but that little left behind is enough
to cause the case to be compromised.

Read: DANGEROUS

You can get some really spectacular case splits....

There were of course exceptions where nobody cared about certain negative aspects of mercury and or chlorate because of some other situational benefit, but generally speaking everyone stopped using those compounds decades ago.

Now the push is to eliminate lead from priming compositions. generally to replace it with either Bismuth or Barium.

AD

quote:

Originally posted by Cheechako:
I'll bet Roger never thought his post would turn out to be a history on primers. But it is/was a very good question Roger.Ray

You got that right, Ray! I truely am glad I started this thread.Wow. roger

quote:

Originally posted by Allan DeGroot:
..."dissolve" is pretty far afield from reality...

is perfectly correct, actually. recall that metal alloys are solutions. amalgams are as well.

quote:

Originally posted by delloro:

quote:

Originally posted by Allan DeGroot:
..."dissolve" is pretty far afield from reality...

is perfectly correct, actually. recall that metal alloys are solutions. amalgams are as well.

I'll still quibble over your "dissolve" because while alloys ar eindeed "solutions" both metals take part in the mingling.

perfectly correct in theory, but not nearly so in scale or proportion, thus my "salt lick" example.

And the mercury will only dissolve so much before an alloy equilibrium is reached and the mixture solidifies.

at issue here is the new alloy formed in a thin layer more like a flash plating is far too brittle and like chrome plating that sticks to soft metal can actually crack in the plating layer and the crack will propagate into the parent material...

Yeah if you put the shell in a bucket of mercury it would dissolve... slowly...