Des Moines test record


#1

This slip of paper came from the Des Moines Ordnance Plant, circa WWII. With it were loaded .30-06 ball cartridges and fired cases showing evidence of high pressure.

I think the information can be interpreted several ways.

The owner suggests that this shows a test of a lot that was rejected due to excessive pressure.

My theory is that this is a test for High Pressure Test cartridges, but these do not appear to have been loaded at DM at any time.

What do the experts say? Chris P.?


AKMS


#2

In lieu of an expert, I will suggest a possible answer !

A lot of people confuse “HIGH pressure test” with “pressure test”. On the face of it these appear to be powder acceptance tests ('cos that’s what it says on the label!). I agree that the label indicates that this particular batch resulted in a high pressure but that does not mean that they were designed as High Pressure Test rounds.

Pressure test rounds were rounds that were used to assess the pressure - including the use of new batches of powder, or a new type of bullet, or case, etc… HIGH Pressure Test rounds were intended to generate a higher-than-normal-service pressure for proofing of weapons.

Chris P.


#3

Thank you for the clairification on that. Where would something like this (the paper, cartridges and fired cases, all together as a set) rank on the rarity scale?

AKMS


#4

Let’s look at the label itself.
Firstly it looks like a stock label used on a regular basis (Typed/mimeographed headings)

Details such as Powder Lot Number, Chyarge of Powder, “Cal .30” etc, indicate that the Powder to be tested was a “4895” or similar Type
The Charge was 47,3 grains (obviously to get the “normal velocity and pressures”

From the extra handwriting, 35 rounds were loaded and tested. it seems the average pressure(CUP) results were 69,130 # ( I take this sign to mean CUPs or PsI, as measured by Copper pellet compression))

Thus the "pressure “rating of this batch(Lot) of Powder was rated as a “High” pressure” Powder for Normal Loading densities…solution…reject the Powder, or reduce the charge weight for the Particular cartridge… More than likely, the charge weight was reduced, as Powder Lots for Military factories run into several (if not more) TONS of Powder…

Normal Factory procedure for each batch of Powder was to match it by Velocity and pressure to the cartridge case and Bullet used…and adjust the charge weight accordingly.

That is the difference between Factory “Lot” Powders, and the Retail “Canister” Powders as described in reloading manuals.

An interesting bit of Cartridge manufacturing Ephemera…and gives a better insight into Military cartridge manufacture…this is distinct evidence of procedures used.

Regards, Doc AV
AV Ballistics.