I have an old 10wt I use exclusively for Kings/Chums. I rarely get it out though. It's not quite "fly friendly" during the fall salmon season. I've brought the bug rod with me MANY times on my yearly salmon fishing trip in October and on the frequent trips in Sept and Nov. But when you're surrounded by gear fishermen, you gotta jump in their boat (which is no problem for me, was raised doing it). Plus, you have to dredge bottom, especially for the kings (though I've had a couple hit a subsurface/dry on springer runs). I hate using sinktips, rather use floating with a weighted fly. But hate either. Rather use a standard WF with a standard tied dry or sinking fly.
But yes, I've caught MANY salmon (mostly silvers and chums) on the fly. In fact, had a little zipper on a route of mine I was catching 4-6 chums in just about an hour fishing during my lunch break. It was funny to see these morons who had no idea what they were doing, and here comes a UPS driver with a bug rod nailing chum after chum, legally hooked. I released most, kept the fresher ones. Have caught alot of silvers and kings, but most are in the salt or in the flux zones of a major river into an inlet.
It's done, but not often (usually there's the religous ones you'll see). I love to hit the cutts, silvers, and chums in the salt/flux. Will be hitting them shortly in fact.