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To: Hardastarboard

“...copper cases didn’t extract properly...formed more like a piece of Damascus steel, not drawn like modern cartridges...” [Hardastarboard, post 70]

Many different cartridge-case designs were tried in the period 1857-1900. Also many metallurgy methods and alloy combinations.

Problems with case extraction were evident from the start: the the first US-made cartridge revolver (Smith & Wesson’s No. 1, introduced 1857) fired the 22 Short, with a small powder charge and very low pressure. Fired cases bulged so badly that the cylinder refused to rotate. The design had to be modified, to incorporate a special disc behind the cylinder, which rotated along with it, to prevent bulged case heads from dragging on the standing breech.

The type of case you refer to was called a built-up or composite design: coiled brass inner layer, covered with copper foil or heavy cardboard, folded metal head like a shotshell, charge sealed inside waterproof paper. The British used these in 577 Snider (cartridge conversion of the muzzle-loading Enfield), early 577/450, and some other chamberings based on the latter.

Not sure if the US military ever used any built-up rounds.

Centerfire military cartridges issued in 1873 look pretty much like rimfire rounds, with a featureless flat face on the head. Priming compound was placed in a cup inserted from the case mouth and crimped from the outside, to hold it in place. The case metal - then copper - had to be thin enough and soft enough to deform when struck by the firing pin, limiting attainable pressure, which wasn’t terribly high by modern standards anyway. The system was developed by Stephen Vincent Benet in the late 1860s, when he was assigned to Frankford Arsenal (he was later Chief of Ordnance from 1874 to 1891).

This was also called “inside priming”. Cartridges made this way were produced in France until World War 2 at least.


77 posted on 06/27/2022 1:23:42 PM PDT by schurmann
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To: schurmann

http://www.cartridgecollectors.org/?page=glossary#:~:text=BENET-PRIMED%20-%20A%20common%20style%20of%20inside-primed%20car-tridge,the%20head%20of%20the%20case%20by%20characteristic%20crimps.

The International Ammunition Association glossary. “Benet priming” is listed; also some other terms I could not recall clearly. Ought to clear up some of the confusion.


78 posted on 06/27/2022 1:34:41 PM PDT by schurmann
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To: schurmann

That was a very good explanation. Thank you for posting it


81 posted on 06/27/2022 4:22:40 PM PDT by Hardastarboard (Don't wish your enemy ill; plan it. )
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