I read those books, the early ones at least, when I was fairly young, and Roland’s literal gunslinging was always a super cool part of the books for me.
In the original Gunslinger, I think the thing which I enjoyed most was the flashbacks to his training, and how the Gunslingers were almost super human in their abilities… You had Roland in Tull killing everyone while they rushed him in a mad mob. This is probably one of the first times they talk about his hands doing their “reloading trick”, which is only vaguely described, but I always took to mean that his training was so complete that reloading his guns was essentially done on a subconscious level. The movie seems to have taken this a bit further, but I don’t mind that.
In later books, there’s generally always at least one climactic gunfight near the end. Like when Roland’s original ka tet went up against the big coffin hunters. The failed gunslinger who led them was a pretty badass guy compared to everyone out there… until they went up against actual gunslingers, who just freaking murderized them. Or the big fight at the Callah, etc. Gunslinging was always a big part of the gunslingers.