Way back when dinosaurs ruled the earth I got my first .22--a Marlin 80C magazine fed bolt action. To me it was almost a Griffin and Howe Springfield sporter.
A few years later I got into small bore marksmanship under ROTC supervision. The rifles available were the Remington 513T, and a few Remington 40Xs which were carefully guarded. But my favorite was the Springfield M2 M1922, built on the M1903 action and expressly built as a sub caliber trainer for the Army in the interwar years. I shot them whenever I could, and many years later I managed to get one of my own. Most authorities believe that they were the finest .22 rifle ever built, with the possible exception of the Winchester 52s. Although I never shot it out beyond 100 yards, some clubs in the Depression shot them out to 2 and 300 yards; I have the windage and elevation tables for those ranges; and the Lyman 48 sights would crank up enough elevation to do it.
Now comes the 15-22 to understudy the AR rifle. Known-distance National Match slow, timed, and rapid fire is a purists' game nowadays for the most part. The real-world is now full of bad guys at shorter ranges, and the emphasis is on quick work and ranges that are almost always under 200 yards. The 15-22 with a red-dot optic is ideally suited to practicing that type of shooting, and for good or for ill, that is what we need to be good at these days. So much for position shooting, use of the leather sling, bolt manipulation, and sight changes. Snipers still practice all those things, but it's become a mysterious art form.
But every once in a while I take out that .22 Springfield with the 1934 barrel date, work the bolt, and admire the craftsmanship that went into it. They don't make them like that any more, and they never will again.