Corrosive Ammo

[ArtPahl]

Too much time to think while sitting on a lawn mower! Maybe this is not the place to ask this but since we collect "Springfields", one of the first things we look at is bore condition. And, is it the original barrel. So I'm wondering why the US waited so long to phase out chlorate primers. The ammo for civilians by the time of WWII had been long since loaded with "Klean-bore" "Rustless", and "Staynless" primers. I remember reading years ago that Winchester offered the use of their patented priming compound for war time use without royalties but the government stayed with the Frankfort Arsenal compound. The thought was the FA primer was more reliable. But non-corrosive priming was reliable enough for the M1 carbine.

Of course Winchester's motives were not entirely altruistic: If we had lost that war, Winchester would have no further need of patents!

Most of the one-time military rifles we see have been arsenal overhauled, often more than once. And a lot of that is due to rusted, pitted barrels. Hard to clean a barrel under field conditions, let alone, combat conditions.

It seems to me that a lot of resourses were wasted for the lack of a non-rusting primer.

Any thoughts or opinions?

Information

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[mtoms]

I read somewhere-so it's hearsay-that the chlorate primers had a longer shelf life.

[Eaglelord17]

Many countries took a very long time to phase out corrosive ammo. In fact China for there Type 95 rifles, they initially used a corrosive primer up to about 2002ish (note the ammo and rifle was adopted in 1995!).

You could say virtually everyone was behind the times after 1911 when the Swiss adopted the GP-11 round as standard (originally designed in 1908), as it was the worlds first non-corrosive issued ammo. This also has a fair bit to do with why the Swiss rifles tend to be in such excellent condition.

Another piece of technology which really changed how people looked at corrosive ammo was when the Japanese became the first nation to chromeline a standard issue rifles barrel. If you look at most Type 99s they tend to have immaculate bores, just because the chrome wasn't effected by the corrosive ammo (or the jungles of the Pacific).

Another thing you have to consider is during war do you really want to be changing something like that? It would require different resources and setting up the machinery differently, which is time they could be making ammo. Most people at the time likely wouldn't have felt it was too big a deal either, being used to using corrosive ammo in the first place.

[Cosine26]

A little personal experience with the FA70 primer.
FWIW
DURABILITY OF THE FA 70 PRIMER
Prior to about 1952 all 30-06 ammo was loaded with what was known as the FA 70 primer. This primer was non mercuric but was considered to be “corrosive”. This primer was very reliable but had one big fault – one of its primary constituent was potassium chlorate. This left a salty residue that attracted moisture and if the barrel was not cleaned correctly would result in severe rusting of the barrel. It was adopted in 1917 after a fiasco with primers led to a large number of cartridges getting to France that misfired.
In the 1960’s I was living in El Paso, Texas and working at the White Sands Missile Range and belonged to a DCM affiliated rifle club. Each year the DCM would furnish us with qualification ammo for each member who fired a qualification course. The ammunition was usually ‘corrosive’ AP (SL43, Den 42 or Den 43). No one wanted to fire corrosive ammo in the M1’s so standard practice was to pull the ammo down and reuse the powder and bullets in reloading ammo for firing qualifications with the M1’s. One year we accumulated a large quantity of Den 42 primed cases and left them in a cardboard box outside the range shack where they endured the heat of summer, the cold of winter, and the occasional rain. They sat there for about two years until I finally decided to take them home.
Curiosity got the best of me so I thought I would see how well the primers had stood the weather. I took thirty of these cases, cleaned them up, neck sized and trimmed them. I then took thirty LC62 NM cases and gave them the same treatment. I used a standard load of 4895 and the 30M72 match bullet. I fired each of three 10 round lots in my heavy barreled M70 target rifle using a 12 power Unertl from the bench at 300 yards on three separate occasions. In all cases the groups were under 1 MOA and believe it or not the corrosively primed Den 42 cases always gave a slightly smaller group than did the LC62 with the new non corrosive primer. (Incidentally Western loaded its Super Match with the 8 ½ G primer which was both corrosive and mercuric for years – well into the early 60’s – I believe because they found that it gave them a slight edge in accuracy.)
Incidentally the Den 42 and Den 43 cases were a little harder than the LC cases (almost like the old “rifle annealed” cases of the pre war years.) and were a delight to shoot in a bolt gun for rapid fire. I would not recommend this but I have de-primed hundreds of these cases and used them for RF. The LC cases seemed to me to have a softer anneal to accommodate the M1. In all of the years that we fired this ammo, I never saw a misfire or a hang fire.

[Gil Boyd]

IMHO There is a lot of corrosive ammo still out there today...........especially some of the 7.62mm x 51 that circulates from Russia and China.

I do not mean to do the Indians any dis service but I do remember a UK MOD contract in the 70's early 80's where we bought 9mm from them, and that was absolutely appaling, I am sure others on here ex REME may have some more detail, but there was a time where all Browning and SMG firing was halted to get the issue rectified. It caused serious issues in the working parts especially with residue. Really needed a strong wire brush to clean the weapons after firing and where many brushs were made especially to tackle the problem which were non issue.

[Cosine26]

I thought that some of the more knowledgeable experts would provide you an answer, but since they have not I shall give it a stab:

Non-Corrosive Primers
When reloadable cartridges first appeared the common calibers were big and used copious amount of black powder which negated the adverse effect that fulminate of mercury (a component of the primer) had on the cases. The case was the most expensive part of reloading (and everyone was a reloader) because most people cast their own bullets out of lead. The advent of the smaller caliber ammo using smokeless powder resulted in the use of much less powder and it created a problem. The mercury formed an amalgam with the brass which was very brittle so that cases did not last long. At that time the Army was also reloading fired brass. It was discovered that mercury was the problem.
In 1897 Frankfort Arsenal developed the non-mercuric FH-42 primer which eliminated the mercury but introduced potassium chloride into the mixture. This primer was used up to and starting the WWI. When ammunition production was increased due to war time demands, problems appeared. Misfires and hang fires became prevalent in ammunition used in France. FA production was stopped and an investigation endued. As a result FA adopted the Winchester 35-NF primer which was re-designated the FA-70 which was used throughout WWII. It proved to be a very reliable primer not adversely effected by high temperatures and was a very durable primer.
Commercial non-corrosive (NC) primers appeared as early as 1901 and the Swiss developed and used NC primers from about 1911. All of the NC primers contained fulminate of mercury. These primers had a short shelf life and the condition of hang fires and misfires was compounded with higher temperatures.
The potassium chlorate created a big rusting problem. It was in 1922 that Dr. Huff discovered that the chlorate was a salt which attracted moisture and resulted in barrel rusting. As a result the FA was searching for a NC primer suitable for service use. Several commercial firms introduced some form of NC primer but they were not fault free. Read the various article in the AMERICAN RIFLEMAN for the 1930's for the details.
By 1930 the FA believed that they had developed a suitable non-corrosive formula and loaded it in 30-06 NM and I&P ammunition. The NC mixture required a larger pellet so the FA developed a Berdan primer for the match ammo. Everything went well until the Nationals. A siege of excessively hot weather, resulted in increase of pressure which created big problems . The NC primed 30-06 NM ammo was withdrawn and a hurriedly loaded lot of NM ammo with the FA70 primer was substituted. The I&P ammo did not seem to give a problem.
Because of this, development of a NC primer was slowed. With WWII in the offing, (remembering the WWI fiasco) the army decided to stick with the FA70 primer. Extremes efforts were made to educate the troops and supply them with adequate material to maintain their firearms.
The exception to the rule was the .30 M1 Carbine. The gas system of the Carbine would not work well with corrosive primers. Since the Army did not consider the M1 Carbine to be a front line weapon, it elected to go with a NC primer which worked out OK. There were small lots of 30-06 ammunition produced by Dominion of Canada using NC primers.
By the 1950's the Army had developed the lead-styphante NC primer which was used from then on and is probably in use today.
That is a brief summary of the development and use of the NC primer in the US military.
Hope it helps.

[Calif-Steve]

I know the Germans fielded non-corrosive primers in WWI. They had a very short life span and had to be used within 12 months. In WWII many German rounds were NC. The US Army could have easily fielded NC ammunition in WWII but elected to stay with the FA-70 Corrosive primer. The Rifle Bore Cleaner the US Army issued was excellent for cleaning but had a very obvious smell. It was so obvious the in Viet Nam the US Army issued a new family of cleaning solvents that were odorless.