GI caliber .30 M1 (rifle) headstamp question

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bamaranger

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I have come into a quantity (200 pcs +/-) of .30 cal (30'06) ammo on M1 clips. Clips are stamped SA (Springfield Armory). The cases are headstamped TW/53. Projectiles are AP (black tips). Couple of questions:

-Post WWII, (1953) but what arsenal? I've not seen a TW headstamp.

-Would this ammo have been corrosively primed? The primers are the dome shaped type common to what WWII era primers, (visually) I've seen.

The lot was pretty rough. I've pulled the slugs and saved same. Cleaned up the clips that were not to far gone. Curious about the headstamp and the NC/Corr issue.
 
own question

I'll answer my own question. A web check yielded a site that listed TW as "Twin Cities.....never saw that before, not sure that I ever heard of it.

First SAFE year/headstamp for NC .30 AP, according to chart by CULVER was infact tw/53.

Stuff I didn't know.
 
Lots of shooting still going on in Korea in 1953, so it's possible that all the corrosive primers had been used. Me, I'd have at least a little concern about "leftovers" from earlier production. I'd shoot 1953 ammo, but I'd do after-shoot cleaning as though they were corrosive primers.

I've read that a problem with once-fired brass that had been loaded with corrosive primers is that of weakening of the brass from chemical reaction with the residue inside the case. Humidity + time = problem.

Olde Phart's memories: From around 1952 or so, I recall newspaper articles about a strike by the union workers at the Red River Arsenal. A while later, there was an article or two about ammo shortages in Korea.
 
Carbine Ammo

All USGI Carbine Ammo is NON Corrosive. The US never made corrosive primed Carbine Ammo because of the Gas Piston Arrangement. Not so for the French. Their Carbine Ammo is corrosive.
Yes TW is Twin Cities
For 06 .30 cal you're safe with anything after 53 . If you're not sure soapy water will do the trick. Just wet a patch with hot soapy water and clean as normal. Different Arsenals had different dates for going to NC primers. TW 51Ball is Safe NC but TW 51 & 52 AP are corrosive . CMP has a great chart.
 
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Twin Cities...
Yes we did have a large ammunition plant here. We are also home to Federal Ammunition.

The site of the old ammunition plant was considered for the Vikings new football stadium but was rejected and the new stadium will be downtown Minneapolis on the site of the old stadium which has been torn down.

One of the problems with the ammunition site was the pollution of the area from years and years of ammunition production but I think when the EPA found out the site would be for football fans they waived the pollution objections under the theory that most football fans' brain cells were already polluted. :D
 
According to the CMP chart, Twin Cities AP went to noncorrosive primers in Feb. 1952.

I never saw anybody but Phil Sharpe to say that AP was harder on a barrel than ball. But Sharpe was one of the leading authorities of his day.

Unlike Art, I have never heard that chlorate "(corrosive") primer residue affected the brass.
 
Jim, not "hard fact"; just something I read somewhere. Back in the 1980s, maybe. But if corrosive primers could hurt barrels from their being hygroscopic, I figure they maybe could react with brass.

My uncle had a gunny sack full of once-fired WW II GI brass. I let it go to scrap in the '80s because it was very grungy inside the case. I figured that tumbling wouldn't help the insides, so it didn't seem worth bothering with. "In case of in case". :)
 
I think there is still a lot of confusion about mercuric primers, destructive to brass; and chlorate primers, risky to steel.
Once upon a time, primers were both mercuric and corrosive. Black powder residue screened the brass from the mercury and wet cleaning of black powder fouling dissolved the potassium chloride. The US Army quit using mercuric primers in 1898. But commercial and foreign practice differed.
There was even a mercuric but noncorrosive primer. The ammo companies were glad to advertise the noncorrosive bit and they did not want to encourage reloading.
 
All USGI Carbine Ammo is NON Corrosive. The US never made corrosive primed Carbine Ammo because of the Gas Piston Arrangement. Not so for the French. Their Carbine Ammo is corrosive.
Click to expand...

Ummm, I think OP is talking about .30-06 for the M-1 Garand rifle, not M-1 carbine ammo.
 
Heh. I don't doubt the "confusion". But I'd say it's ignorance due to a lack of readily available factual info. It's not an everyday subject of discussion. :)
 
NC Primer

Jim, you are correct that TW Arsenal acceptance of noncorrosive primers was 2-52 lot #19776 . The Question remains , did they discard their stock of corrosive primers or did they continue to use them until stocks were depleted ? Given the date was 2-52 that means that 1-52 was corrosive primed. Being that TW Brass is not marked by month but only the year one would not know if it was made in January -corrosive or June -noncorrosive. To be safe I would not assume TW 52 is noncorrosive.
Ball and AP have the same gliding material jackets . The difference is Ball is lead core and Armor Piercing has a Tungsten Carbide Core. I don't think AP will hurt the barrel at all.
Tracer is hard on the barrel due to the Phosphorous
 
I would also assume any TW52 not in lot numbered packaging to be corrosive.
The OP has TW53 which is noncorrosive.
I have not seen anything to indicate a trickle of leftover chlorate primers going into production.

To quote a usually reliable source (me), I never saw anybody but Phil Sharpe to say AP was hard on rifle barrels.* Hatcher says early postwar matches were shot with selected lots of service ammo and AP was usually more accurate than ball.
But the Army had plenty of spare barrels.
I think WW-II AP has a hardened steel core, tungsten carbide was too valuable in machine tools to shoot at foreigners. I can check tomorrow.

*Complete Guide to Handloading, 3rd Ed., 2nd Rev., Supplement, pg 142
 
That edition of Sharpe is one of the best references I know of. I still recall the "A" I got on a high school theme paper, using it as a primary reference. It was a Bible for my reloading, those long decades ago. :)
 
No, corrosive (potassium chlorate) primers won't harm brass but mercuric primers will, since the free mercury resulting from firing amalgamates with the brass and weakens it. Many of the "non-corrosive" commercial primers of the late 1920's and 1930's were mercuric (Winchester Staynless being one), but by the late 1930's, companies had gone to lead styphnate for their commercial primers; they used the required FA-70 formula on military contracts and it was was corrosive.

Why didn't the Army go to non-corrosive primers sooner? Because some of the early primer formulas were not stable, and only time will determine stability. The Army, unlike Joe Hunter, had to stockpile millions of rounds of ammunition, under conditions ranging from frigid Alaska to tropical Panama, and it had to last a reasonable time. They definitely didn't want the country to go to war and have soldiers find out their ammunition had dead primers.

Jim
 
I have read that with commercial ammo, M1 Carbine ammo, and some contract .30-06 from Canada doing well, that the Army was satisfied with the stability of styphnate primers by the end of WW II and meant to change over in 1950 as stocks of chlorate primed ammo were depleted by age or training. But the Korean War intervened and they stuck with what the arsenals were tooled up for for a few more years.
 
Carbine ammo was non-corrosive because Williams and Winchester told the Army flatly that if corrosive primers were used, carbines would be ruined. And the Army considered the carbine very much a temporary and secondary weapon and was not too concerned about ammo stability. Also .30 Carbine was not used in machineguns or any other weapon and in combat a useless carbine could be replaced quickly with a rifle.

But the carbine ammo did prove that non-corrosive primers would be stable and usable in combat. Plus, the Army had pre-war non-corrosive primers that had by the end of the war been in storage as a test for almost ten years, so by 1950, the Army was ready to acknowledge that non-corrosive primers were sufficiently stable for military use.

Jim
 
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