Interesting read on .38 vs .45 -
http://morolandhistory.com/Related%20Articles/Legend%20of%20.45.htm
I was approached by a grizzled and somewhat scary looking old Moro gentleman. A colorful and garrulous fellow, he regaled me with tales of his time as a guerrilla warrior in World War II fighting the Japanese. At one point, he pulled up his shirt and pant legs to show me the many bullet wounds he had sustained, more than half a dozen. When I marveled at his ability to survive such damage, he proudly boasted in broken English, "Well you know, we were the people your Army had to invent the .45 automatic for!"
In mid-1903, the jurisdiction of the Philippine Constabulary was extended to the lands of the Moros through a newly-formed subsidiary organization called the Moro Constabulary. In early 1904 the Moro Constabulary fought side-by side with the U.S. Army while serving as scouts against the Moros. In his Annual Report of June, 1904, General Leonard Wood stated what he thought was obvious to anyone paying attention.
'It is thought the .45 caliber revolver [meaning the Constabulary Model 1902 ] is the one which should be issued to troops throughout the Army. Instances have repeatedly been reported during the past year where natives have been shot through and through several times with a .38 caliber revolver, and have come on, cutting up the unfortunate individual armed with it. The .45 caliber revolver stops a man in his tracks, usually knocking him down. It is [also] recommended that each company serving in this department be furnished with four 12-gauge Winchester, repeating shotguns. For outpost duty and advance guard [walking point] there is no weapon in our possession equal to the shotgun loaded with buckshot.'
.45 colt can be loaded from 300 ftlbs to 600. Both loads will drop an out of control horse. Great round. Very cool.