[alyeska338]

While I don't have a direct answer to your question, I do have an article G. Sitton wrote some years ago about a custom short barreled 35 Whelen Imp he had built. The rifle was based on an FN Mauser action but sports a 20" barrel. The article is about 4 pages long and gives loading data for about 30 loads using 8 different bullets in 4 weights and 7 or 8 different flavors of powder. He doesn't go into exactly how much volume difference there is between the Whelen and the Imp, but if you are interested, I can get a copy of the article to you, either snail mail or email. Sitton really liked the rifle and chambering, but says in the last paragraph that he intended to give it to an outfitter friend of his.

Let me know if you are interested.