Thursday, February 12, 2015

The Cartridge Debate, Part III: A Divergence

I have many more profound things to say about the New Conventional Wisdom of handgun cartridges, but alas I have been sidetracked by knowledge that has descended upon me by podcast. Woe is me.

I have to thank the PowerFactor Show podcast for rejuvenating my interest in the 10mm cartridge. I've always liked "magnum" cartridges, which the 10mm by power alone (and not development from) definitely qualifies. It is not a "magnum" derived from a lesser, a la .38 Special to .357 magnum, but definitely is in the magnum class.

But its origins definitely bring into question the "conventional wisdom" of "adequate" power for defense.

So for the sake of studying the 10mm in the pantheon of service cartridges, I require a little revisionist history to help me get my thoughts straight.

The 10mm Cartridge, A History:

Everyone knows that the 10mm pistol cartridge was created by Col. Jeff Cooper (Ret.), was introduced in the Bren Ten, and was adopted by the FBI for a short time after the famed Miami Shootout.

But according to a few sources, the "real story" goes something like this: Col. Cooper wanted to create a gun that pushed a 200-grain bullet to a 1000-feet-per-second impact velocity. That performance approximates what the .40 Smith & Wesson cartridge turned out to be.

Is that true? Is any of it true? Let's see.

I found a few sources that stated that Col. Cooper did call for the development of a .40-caliber cartridge that pushed a 200-gr. bullet to a 1000-fps impact velocity for a semiauto. Apparently, Col. Cooper specified a muzzle velocity of 1050 fps to achieve that performance at 50 yards. He then pushed the muzzle velocity to 1100 fps as cushion to achieve performance. He wanted to have a pistol like the Browning Hi-Power chambered for the cartridge.

Well, it seems a little more complicated than that, according to a forum exchange on, and quoted or paraphrased by Cal4D4:

"In the early 1970's an individual by the name of Whit Collins started looking at the feasibility of rechambering the 9mm Browning Hi-Power to a more powerful cartridge. Originally he was considering the .38 Super, but Col. Cooper's idea of a 200gn bullet of .400" diameter traveling at 1,000fps changed his thinking. Whit Collins did a lot of work just looking into the feeding geometry to see if a .40 caliber bullet could be made to function. When he was satisfied that it could he began looking for existing rifle cases that had the proper casehead dimensions and could be trimmed down to proper length for the Hi-Power magazine. With his drawings and some "dummy" loads made up he approached Jeff Cooper about his idea. Col. Cooper lent his support to Mr. Collin's idea and with investigative and research help from Guns & Ammo the project moved ahead. Next came assistance from Irv Stone of Bar-Sto and master gunsmith John French and by 1972 a Browning Hi-Power chambered in .40 G&A was being test fired. The loads being fired consisted of a 180gn bullet at 1,050fps out of the 5" barrel. In 1973 Col. Cooper and Mr. Collins started talking about a longer cased .40 caliber round that would be developed with the various .45 Auto platforms in mind. At this point Whit Collins went on to continue working on his .40 G&A and Jeff Cooper began his work on what was being called the .40 Super. A number of years went by until 1978 when Col. Cooper teamed with Thomas Dornaus and Michael Dixon. Via the Bren Ten semiautomatic pistol the .40 Super evolved into what we now call the 10mm Auto and the rest, as they say, is history." (This comment references the following deadlink

So D&D agreed to develop the gun, and they patterned their contribution after the CZ75, which was "inspired" by the Browning Hi-Power.

Norma signed on to create the ammo for the D&D Bren Ten pistol. Norma upped the ante with velocity by increasing it to 1200 fps at the muzzle. D&D requested more. Norma settled on 1250 fps and wanted to get into production.

The Bren Ten basically flopped, was pulled from "Miami Vice," the FBI had a bad shootout in Miami, the FBI chose the 10mm and the S&W 1076, the FBI quickly chose the downloaded "10mm Lite," because the full-power 10mm loads were too much for some special agents, and the .40 S&W was developed as a replacement for the "10mm Lite" to accommodate smaller hands, to take advantage of the reduced need for powder volume, etc.


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