Mine was a S&W Sigma 40. (It was also the first handgun I shot)
I'm gonna stop you right there, you just said an AR-15 is a high-powered rifle. It is obvious you don't know anything about guns and I shall ignore anything you say from this point on.
Mine was an S&W Model 36. Got it at our local police supply in 1981. It was nickel. The cylinder started to pit at the indentations after only 13 months. I took it back and they sent it to S&W. The gun came back looking better than it did new and stayed that way. It has another home these days.
SA XDm9. Loved it until I shot a glock. The thicker grip just did it for me. And it's weird because I don't have huge hands. ???? But everything else about the XDm is better than a glock. Kinda miss that gun.