Got 338WinMag and 375H&H, but got no single shot high power rifles.
Other than a smoke pole I'm ready to get rid of, I don't own a single shot rifle, shotgun, or pistol of any sort.

Really, I don't consider myselfperfect enough to feel good about utilizing single shot rifles for any sort of big game hunting.
I'd take the Howa in 338 WinMag.