When the US Army started testing bullets that eventually lead to the adaptation of the .45 ACP in a Colt 1911, they had a unique way of testing that may be frowned upon in this day and age. The Army, which favored "shock value" in bullet performance hung cadavers by their heads and fired shots at them, recording the cadavers reaction. After much testing the .45 ACP beat out the .38 Caliber entry. They used a scoring system of 1-100. The .38 caliber entry scored between 50 and 65, the .45 caliber entry scored 80 or higher. They also used live cattle for the bullet testing.
BTW, after the .45 bullet was chosen, Colt and Savage pistols went into a head to head competition to become the US Armed Forces service pistol. Colt won the competition, which involved firing 6000 consecutive rounds, with cleaning after every 1000 rounds fired allowed. The Colt 1911 fired all 6000 rounds without a malfunction, the Savage suffered 31 malfunctions.
If interested in reading more about this pick up a copy of; The Guns of John Moses Browning by Nathan Gorenstein. It's a fascinating book about a firearms genius.
