I want to load 5 boxes of 7mm for a buddie in TX that I hunt deer with. He has a Ruger M77 SS bolt. I used this rifle last Dec at his ranch and shot it quite a bit to get use to the rifle so I want to replace the ammo and have plenty to use again this fall. The problem is without having the gun here how do I work up a load for it? Any suggestions on OAL, gr of powder that might be acceptable for his M77? I have new Rem brass and 4831Sc, and 4831 powder and 140 gr Nosler Partition bullets that work great in my 7mm.