I have no personal experience with reduced loads in the Whelen, but Mule Deer published an article on reduced loads and included this one for the Whelen:
(Remington case, WLR) 200 Hor RN, 36.5gr / IMR4227, 2197 FPS, 1.12" av group. If you substituted the 200gr SP you'd probably have your 200 yard criterion - might even have it with the RN.

Cheers,
Rex