Hi, That is a great caliber.
I am using IMR 4350 and 130 ABs. Chrono out at 3054fps and .675moa @ 100 yards. rifle is a CDL 24" tube. I have been shooting this caliber since I was 15 years old so I guess that makes it over 40 years. Most calibers have a pet weight of bullet and I believe it to be 130 gr in a 277 also most of my loading material tells me that 4350 is go to in in the 270. I am also using in the 7mm mag and now in a 300wsm. My Motto is if it ain't broke don't fix it
I do not think that H-4350 would be much off that but I would likely start a little lower and work up.
As I just stated we are leaving for Elk early tomorrow and I am using up the last of my Partitions when they are finished only ABs out of my rifles :wink:
Another vote for H4831SC with Federal Magnum primers. Of course you have to work up your load with those since they burn a little hotter and longer than regular large rifle primers. My buddies .270 used 130 gr. Partitions or Accubonds and 59.0 grs. of H4831SC.
I messed with IMR4350 a bit with standard large rifle primers and they showed excellent potential as well, but I was getting 3/4 inch groups with his light barreled Remington Mountain Rifle so I stayed with what worked!