Let's compare the M1911 to a popular service revolver used by the many police forces of the dat.

An easy choice would be the Colt Official Police, most police forces would likely use the .38 Special version due to the popularity and availability of the cartridge.

From a cost perspective, revolvers are much cheaper than their automatic counterparts, requiring less moving parts and an overall simpler construction.

Let's look at caliber as well, the .38 special was a very popular handgun round for not only police, but civilians as well, making the round cost effective and readily available, something that is very important when most of the U.S.'s munition factories are cranking out .50BMG, 30-06, and .45 ACP.

The M1911 however fired the .45 ACP round, which had not received as much commercial adoption at that point. From a logistical perspective, the .45 ACP round made more sense to the U.S. Military as well since the M3 Grease Gun and M1A1 "Thompson" also fired the same round as the M1911.

Despite the M1911s incredible reliability (during its evaluations, it reportedly had no failures over several thousand rounds fired through it), there was a distrust for automatic handguns as they required the weapon to manually cycled if a round failed to fire, in the case of revolvers, you could continue squeezing the trigger.

Police Didn't need a new handgun, and while popular culture depicts criminals and outlaws being loaded to the teeth with powerful small arms during this time, that wasn't the case for many smaller municipalities and towns. In addition, many major cities, such as Los Angeles, had shotguns such as the Ithaca 37 in their patrol cars, giving them extra firepower if the need arose.