The 25 souper is a neat little round I don't have the data in front of me I'm about 650 miles from it right now
the 25/06 has more powder space so it's gonna be faster that's just a given it that whole cubic inches thing like drag racing. Might try a search on it I just got in so after a shower and some food I might see what I can find. My smith has one and loves it for these Okie deer he's a huge fan of the 25/06 but he siad he can't see a good enough reason to build one since he has his souper. Later,
Kirk

Kirk