I started law enforcement with a revolver. When we finally adopted a semi-auto a few years later, it was the new S&W 645. I also carried a 1911 when assigned to an undercover narcotics unit for a time, and later a Glock 21. When we had the revolvers, we carried .357 magnum ammo. The .45's were JHPs. It should be noted that virtually none of us would carry 9mm in those days because of perceived ineffectiveness based on shootings where multiple hits (one upwards of 30 rounds) failed to stop the bad guy. Over-penetration was common, along with lack of proper expansion (refer to the 9mm Silvertip).
Now, with all of that out of the way, my preference has always been .45 ACP. I grew up in a military family and had a father who firmly believed the 1911 and .45 ACP were the best there was. Over time, technological and ballistic advancements brought the effectiveness of 9mm up to an acceptable level. Us "old cops" began to grudgingly accept them, with the right loadings, but still clung to our .45s, particularly 1911s among my friends. The one thing I always remember from those days was while in a class with Clint Smith, there were a number of Sheriff's Deputies who were issued S&W 659s in 9mm. They were making fun of my new-fangled Glock 21 (as was Clint, it not being a 1911). I asked Clint to explain to the Deputies why he carried a .45 ACP. Not a direct quote, but his response was something akin to, ".45 makes bigger holes, bigger holes leak more fluid). Clint also told us that .45 FMJ was his preferred carry because 9mm had to expand to be effective; .45 ACP didn't need to.
of course, followed closely by my 1006
