303 Ammo

[treeman]

With plenty of work, but why would you want to use cases made with such a crappy alloy anyway? When reloading old brass, consider when and for whom it was made.

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Much wisdom.
Consider when and for whom it was made + what its entire purpose was back then.

[Peter Wells]

Roger, thanks Peter. The 70% story re. WW2 ammo production relates rather to the U marked ammo not SAM.

Peter, the WW II headstamp was U. SAM came post-war.

Peter

[A-R]

That is interesting. How accurate are these cordite rounds? ...

I had a batch of 500 post-WW2 Cordite ammo (SA-made) that I bought from the old SADF when they still did sell ammo to reserve members. They used the old flat-base MKVII bullet. (Later ammo like the A80 stamped one likely had the newer boat-tailed PMP bullet. Will need to pull one to confirm.)
This ammo was quite accurate, by 303 standards. In a good rifle they should do 1MOA. The only issue was that on a cool day, they tended to produce delayed ignition. On hot days this was less noticeable. This caused me to use them less, and with age they got worse. Eventually I pulled all the remaining bullets for future use.

Also keep in mind that the Cordite burns very hot and tends to pit a barrel within just a few hundred rounds. I would not use them in a shiny bore. And keep in mind that the priming compound is corrosive and needs to be diligently cleaned out of the barrel to prevent damage.

[High Power]

Also keep in mind that the Cordite burns very hot and tends to pit a barrel within just a few hundred rounds.

It doesn't pit the barrel, it burns it away! The lands wil start to crumble and break and the rifling leade will move down the barrel. There is nothing you can do about this except to NOT SHOOT cordite.

Why do you think that the army used to keep fitting new barrels?!

Peter

[treeman]

It doesn't pit the barrel, it burns it away! The lands wil start to crumble and break and the rifling leade will move down the barrel. There is nothing you can do about this except to NOT SHOOT cordite.

Why do you think that the army used to keep fitting new barrels?!

Peter

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I do believe you are correct.
It was the primers that pitted the barrel. If you look up my old .303 threads you will find some pictures of a very new pitted barrel I split open to study.

[High Power]

It was the primers that pitted the barrel.

Yes. it was corrosive primers. In black powder times the boiling water used to remove the fouling also washed out the corrosive primer residue. However, water ceased to be used once cordite and similar nitro propellants came into use. Wiping a barrel out with oil etc did not remove the primer residue!

Peter

[A-R]

It doesn't pit the barrel, it burns it away! The lands wil start to crumble and break and the rifling leade will move down the barrel. There is nothing you can do about this except to NOT SHOOT cordite.

Why do you think that the army used to keep fitting new barrels?!

Peter

I believe you are quite correct Sir.

[treeman]

Yes cordite burns the barrel due to its insane burning temperature.
Corrosive primers pit a barrel.
A combination of the two did a barrel in, in no time, the readings on subject are rather eye opening. I can not recall the figures, but the military expectancy of barrel life at the time was very " Is That all? ".

I recall reading the figures and thinking "it must be a miss print", till it was mentioned again else where.

I can say now, further down the .303 line of exposure, that a burnt barrel is a pretty shitty useless thing, but a pitted barrel can still produce some awesome accuracy.
I have now met a few old barrels that shoot well, but if you run a brush down barrel and know what to sense, they are gravel roads in barrel/roads terms.

My .303 with 16 inch barrel and rifling that looks like plucked chickens skin shoots a easy sub one inch at a 100 m
I WILL BE HARD PRESSED TO JUSTIFY SHOOTING OLD CORDITE AMMUNITION DOWN ANY BARREL THAT SHOOTS WELL, REALLY, WHY? - WHY WOULD YOU?
Just not worth it.