POTD: The Evolution of Self Contained Cartridges

   04.03.21

POTD: The Evolution of Self Contained Cartridges

Welcome to today’s Photo of the Day! Today we have a Justice League-Esque-looking photo from a Curious Relics article published a while back on pinfire ammunition. In this lineup of cartridges, we have 7mm Pinfire, .30 Rimfire Short, .41 Short Colt, and a modern 38 Special. The significance of this lineup is it covers a broad overview of self-contained cartridge evolution through a few hundred years. Before brass casings, there were paper or cardboard hulls. Eventually, it became so much more than that and a lot of it started in the era of Pinfire ammunition. The first initial iterations of that were made out of cardboard.

Pinfire was a cartridge design in which a pin would be driven down into the case by being hit by a hammer and would punch a primer on the inside. As you can imagine the people with efficient minds thought to cut out the middle man which was the pin and they came up with Rimfire which would incorporate a priming compound within the end of a casing and a certain required force would make it become volatile and set off a spark. Centerfire took the primer and put it on the rear of a case and placed the pin on the end of a hammer. Easier to store, handle, and better overall function of a mechanism. Speaking of mechanisms this all opened the door for new fantastical firearm designs. Read more on Pinfire Ammo here.

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