Originally Posted by S&W HE

The little bullet going fast, big bullet going slow argument started in 1896 after the Army replaced the 1873 single action Peacemakers in 45 Colt with the new double action Model 1896 Colt 38. Due to failures to stop, the Army re-issued the 45 Col Peacemakers. The results from 1904 Thompson-LeGarde tests and the 1907 Pistol Trails reinforced the big bullet performance. (PM me with your email if you'd like copies of these historical documents. Warning: The Thompson-LeGarde Tests are gruesome.)

And interesting side note, the attached 1933 Bureau of Investigation letter supports the little bullet theory. Of course to write this letter Special Agent J.M. Keith had to ignore the results of the Thompson-LeGarde tests and the Pistol Trails as well as the 1911 45 ACP World War I track record. And he cites bullet weight in grams, not grains. Might want to convert 158 grams and 200 grams into pounds.

After 40 years the ammo manufacturers have developed 9mm cartridges that meet the 1975 (updated in 1985) National Institute of Justice's Relative Incapacitation Index findings. A study based on hypothetical assumptions and a computer-generated man and rated the 115-grain, 9 mm FMJ round twice as effective as a 230-grain .45 ACP FMJ.

So what's this all meammn. You can find lots of information to support your side of the 121 year argument... and carry the round you trust and are most comfortable with.