H-4198 under 250gr monoflex for 2600 fps or 300gr TTSX for 2450 fps, either would clean 250-300 yards with ease, AA-2230 may get you there too, albeit compressed loads, which i dont mind at all.
As with Odonata's brace of rifles containing the 303 British, 9.3x62 and a pair of 375's, augmenting arms to go with the great 458 WM is all part of the fun, being accused of being a facilitator is never a bad thing, the 45-70 is certainly in this group.
