One of the things that gripes me is someone posts a set of parameters and asked which one. Then someone else jumps in with something not covered in the parameters. This must make me a bit of a pypocrite because here I'm going to do just that. Suggests some alternatives.
Me? I'd forget the WSM and the Acklet wildcat. For one, I don't think the .270 WSM will hand around and could go the way of the Dodo bird.
Second, the .280 Ackley is a wildcat round and if you decide to get rid of it, the monetary loss could be substantial.
No, if it were me, I'd look at the plain old .270 Win. or .280 Rem. and never look back. Both rounds can be handloaded to improve their ballisitics, especially the .280 which is underloaded due to it's use in semiautomatic rifles. Either cartridge, properly loaded will be more than adequate for the type of hunting specified. Ammo will be less expensive, especially in the .270. If the rifle choice were mine, in either cartridge I'd go with a tuned up Ruger #1B with 26" barrel for top velocity. I'll bet that with one of those rifles, I can come awfully close to the .270 WSM with the standard .270 Win. round and push a .280 Ackley as well. Currently, I have an FN Mauser in .270 Win. that will push a 150 gr. Nosler partition to 3000 FPS with absolutely no signs of pressure whatsoever. (It ain't for sale, sorry.) It will put 5 rounds under a nickel with the first three under a dime. The only bullet I have worked with in the .280 rem. is the 175 gr. Hornady Spire Point and it too is a tack driver. I haven't chronographed the load yet. Both the mentioned rifles have 24" barrels.
Anyway, that's the way I would go. FWIW, 150 gr. in the .270 Win. and possibly the 140 gr. in the .280 Rem., both using the standard cartridge.
Paul B.