I have a new 20" 7mm08 on the way,and will either be loading H4350,or IMR4064 ,and Hornady 139gr Interlocks,or 145gr Hot Cors .I have used both,and have gotten good accuracy from both with my other 7mm08 rifles, I don't own a chronograph,so I can't speak of velocity,but I have encountered flattened primers when approaching max with the 4064,and never showed any pressure signs even with a compressed load of H4350 .I realize there is a good bit of difference in burn rates of these two powders,and have hears some folks state that a short barrel will give incomplete burn with slower powders,and I have heard some say that is nonsense ,so I would appreciate the opinions that any of you care to offer...Thanks