For what it's worth (and given my knowledge and experience, it's likely not worth much) I regularly use an Ithaca-made LeFever Nitro Special for clays and hunting both. I'm a firm believer that you should "train how you fight" with the "fight" in this case being upland hunting. It's a boxlock (very similar to an A&D setup) which I purchased well used from an auction about 3 years ago. It performs extremely well and I have yet to see any signs of wear on it. It's a basic mass-produced US SxS. It's not pretty, it's utilitarian for sure, but it'll break clays and put down birds just as well as anything else. I'd be very hard-pressed to put a fancier or finer gun into service for clays and clays alone unless I was competing.