The Whelen Improved is outside my knowledge but the .35 Whelen is not - I had an 8mm Yugo 98 Mauser customized/sporterized in the 1990s into .35 Whelen. It is DEATH on pigs. I could go on and on about the custom rifle itself, because it's gorgeous, I have a Leupold 1.5 x 4 scope on it (I forget where it's set but I never change it), but my point is that I had it built for elk, sadly so far unused for that, but I have used it on feral hogs with spectacular results.

***GRJ***