I have built quite a few rifles for people in this caliber. It works great from an accuracy standpoint and has great killing power, but isn't significantly more powerful than a regular 35 Whelen. There's just not that much more room in the case. What it does do is give much beter headspace control and far better accuracy than a factory chamber. Just use normal 35 Whelen load data, and work up carefully over what the books list, paying attention to what your rifle is telling you. If you get someone to set it up properly, you'll love it. Just make sure their reamer has a properly sized throat - unless they custom speced it the tool makers are making those throats huge for some reason, like .363" for the off the shelf Clymer reamer.
