My first handgun was a Ruger Standard .22 in 1965. Lousy trigger but the gunsmith at the USAF Academy range cured that. 2nd was a Ruger BH .357, a good gun that I later sold to my sergeant in the USAF....he's still got it and brought it along for a visit several years ago.
Our Academy pistol team shot Hi-Standards...Citations IIRC, with 1911 Colts, heavily gunsmithed, in the centerfire & .45 matches. Ammunition was free and we shot a lot.
Our team sergeant, CMsgt Ed McFarland, could break ten cent balloons on the 100 yd rifle berm with his .45...and this was just the balloon, not a 4'x4' piece of steel with the balloon in the middle. He would also split a .45 LSWC on an ax blade at 50' for distinguished visitors, breaking a clay bird on either side. Hellofa shot in his day, a great coach and mentor.
The 60's were 99% revolvers in police use with 1911's in the Army & Marines with S&W revolvers issued in the USAF. S&W's were half again more expensive than Rugers at the time so on my limited military pay, I was a Ruger fan. At the time, aircrews were issued an alloy snub nosed .38 Spl. S&W, with hardball ammunition, and that's what we qualified on in '64. (A gun much desired by serious S&W collectors nowadays.)
By '65, the USAF had transitioned to Smith M-15's...a far more useful piece, generally...and that's what I was issued after arriving in Vietnam. In my case, I left the gun with the squadron armorer in Bien Hoa, and used a Special Forces supplied 1911A1 while up-country in the bush. When my predecessor DEROS'd in April of '70, I inherited his Browning Hi-Power and the 'tanker' rig for carrying it...I used that for the remainder of my tour; carried that 100% of the time in the camp up on the Cambodian border, and while flying on patrol.
Somewhere in that time frame, S&W came out with the Model 39, auto-loader...really the first of the generally available autos here in the U.S. that I remember. There were a smattering of European guns around, Walthers, and the occasional Luger bring back, but that was about it...revolvers ruled, in the field & on cop gunbelts, though the '70's.
My experience was with customized 1911 on the ranges, & with some combat time as well. Never shot it in anger, but liked the gun (still do!). Now in my old age, the Browning was and continues to be the crème del la crème of auto's for feel and shoot-ability. I liked its capacity for combat use, but regarded the FMJ 9mm load as a distant 2nd to the .45's we were issued. Butt, truth be told, either was a comfort while crouched in a slit trench, listening to the faint tinkle of the cans strung out in our defensive wire.
Just some reminiscences....YMMv, Rod