I am with 260Rem on this one. I just got my Nonneman 356 conversion back last week. I just posted a thread on it with pics. I recommend him highly for anybody wanting this done - or other lever work for that matter.
I see nothing wrong with pumping the 35 Rem up some as it is underlaoded but you are talking a 200 grain bullet at 2300 fps - max.
The 356 at normal pressure (similar pressure to +P 35Rem) will deliver 2650 fps with the same bullet. That flattens trajectory within iron sight range considerably and needless to say elevates the rifle to the next power level without any plus p worries.
I've got a 35Rem Marlin too and I load that to normal pressures and get 2000 fps with 200 grain Rem Corlokts - a good deer load and very fun to shoot.
Maybe now I'll get a 35 Whelen...
