10mm American Hunter article

[Rojo27]

Another 10mm article.

https://www.americanhunter.org/articles/2016/10/28/behind-the-bullet-10mm-auto/

[PCFlorida]

Another 10mm article.

https://www.americanhunter.org/articles/2016/10/28/behind-the-bullet-10mm-auto/

It was interesting, but when they started talking about "and the fact that very few modern pistols are being chambered for the 10mm Auto" it could have been written 15 years ago.

[The_Shadow]

Well some of the facts are off base when it came to Col. Cooper's original specs for the velocity...

In the early 1980s, Col. Cooper sat at the drawing board to develop a cartridge of suitable diameter, which would drive a 200-grain bullet to a muzzle velocity of 1,200 fps

His original specs were for

The renowned Colonel John Dean "Jeff" Cooper, had the inspiration of a 40 caliber cartridge which would drive a 200 grain projectile @ 1000 feet per second which would translate into 444 foot pounds of energy

It was Mike Dixon that was able to finalize external specifications; he also upped the velocity specification to 1150 feet per second, which exceeded Col. Cooper's numbers of 1000 feet per second and Dornaus wanted the numbers low for fear of reliability. 

Suggest reading more here; http://rangehot.com/original-10mm-ammo-made-ffv-norma-ab-%C2%B7s-670-40-amotfors-sweden/

[The_Shadow]

You can also gather an appreciation from this article from back in the day!
http://10mm-firearms.com/10mm-semi-auto-handguns/sw10xx-series-information/msg1632/#msg1632

[Mike_Fontenot]

I THOUGHT I had read a few years ago that the original FBI 10mm requested load was upped significantly by (I think) Norma.  Which load was tested by the FBI and found to be too stout ... the original requested specs or what Norma came up with?  (I THINK Underwood today is essentially the Norma level).

[The_Shadow]

This info comes from the "FBI's 10mm Pistol" by John C. Hall, Special Agent, Firearms Training Unit, FBI Academy, Quantico, VA  November 1989.

FBI had some ammo commercially loaded 10mm for their testing, which was hotter than they originally settled on which was a 180 gr JHP @ 950 because it drastically reduced blast and recoil.  Thus the "10mm LITE".
The early testing was said to be skewed by some of the testing personnel because they 45 and 10mm were tested from 6" barrels originally.  The immediate concerns were that the longer barrels would provide an advantage with increased velocity.

Just like we have found the increased velocity actually decreased penetration in most instances.   
After 40 shots the 10mm returned a 39 out of 40 shot test result was 97.5%  meeting or exceeding the 12" minimum penetration where 18" maximum was desirable.

Eight 5 shot test were used for each;
1 Bare Gelatin @ 10'
2 Heavy Clothing @ 10'
3 20 Gauge Steel @ 10'
4 Wallboard @ 10'
5 Plywood @ 10'
6 Auto Windshield @ 10'
7 Light Clothing @ 20 yards
8 Auto Glass @ 20 yards

Commercial ammo back then was;
NORMA 170 gr JHP @ 1350 fps from the Colt DE 5"
Federal 180 JHP @ 931 fps from the Colt DE 5"
Federal 180 JHP @ 922 fps from the S&W 4516 3 3/4"
Winchester 180 JHP @ 931 fps from the Colt DE 5"
IMP-3D 180  JHP @ 991 fps from the Colt DE 5"
Buffalo 191 Pre Frag @ 914 fps from the Colt DE 5"

As tested from the 1076 4.25" June 1990 as reported in the American Rifleman
Federal XM1001 180 gr JHP @ 908 fps
Federal HydroShok 180 gr JHP @ 927 fps
Hornady 200 gr XTP @ 1005 fps

[Olgo]

Commercial ammo back then was;

Federal 180 JHP @ 931 fps from the Colt DE 5"
Federal 180 JHP @ 922 fps from the S&W 4516 3 3/4"
Winchester 180 JHP @ 931 fps from the Colt DE 5"
IMP-3D 180  JHP @ 991 fps from the Colt DE 5"

That's pretty much the same specs of today's 40sw.