I served in the post-Vietnam Army (1973-76). While I was always interested in firearms, the only time I ever got to shoot was at Boy Scout Camp. I really knew nothing about firearms when I enlisted. The first centerfire rifle I ever fired was an M16A1, the first centerfire pistol was a M1911A1. Being bigger than most soldiers I always had an M60 Machine Gun issued to me as well. I was impressed with the range of 900 meters (rather than the 300 of the M16A1).
When I left the Army, I started reading (pre-internet days) and I was surprised to learn of the AR10. I wondered why the Army didn’t have AR10’s too, for use in future theaters that would require longer range weapons (like, as it turned out Afghanistan).
Anyway, I like the 7.62 NATO/ .308 Winchester cartridge. It’s the most powerful cartridge I use and I have a Savage 99, a Ruger Gunsite Scout, a S&W M&P10, and my favorite, my ArmaLite AR10A2 Infantry Model, all in .308.