I suspect that Lyman is being overly cautious regarding the #3 loadings. There are different 1895's in circulation. They (and their lawyers) are terrified that someone will insert one of their #3 loadings into a 100 year old Marlin 1895. The only remedy for that would be to add two more sub-categories - "Pre and post 1972 Marlin 1895" - to their manual. I can see why it's easier for them just to hold their position with regards to #1, 2 and 3. I myself would not be afraid to fire a #3 in my new production SBL but, having said that, there's really no valid reason to do so. Plenty of power with hot #2's...and like someone said above, there's no benefit in putting more stress on your rifle and abusing your shoulder.