I had a Hornady Load Manual, back in the late 70's, that showed several loads for 3400fps with their 139SP in the Rem Mag. My rifle had a 24" barrel, and I had no chronograph...so you bet! ha I later went to the 140 NBT and got pretty close, but not with a 24" barrel, ha. I too had a Ruger 77 in .280 that got me started in handloading. I killed a buck at 276 long steps down a pipeline. I killed a few others under 30yds. I then sold it ( my wife had given me a Mod 700 BDL for Christmas) and used that rifle for about 10 straight years. I never killed anything with that particular rifle past 30yds, but it was heavier, longer, did not swing or handle as fast as that Mod 77. I "still" hate the flat bottom of the stock at the receiver on Rugers!
For me, its the rifle, then the cartridge. different styles of hunting is all. Later in life, I killed a wad of game with a .280 Mod 700 Mtn rifle reamed to the AI, but it still was 2950 with a 150NBT. The uncut chamber .280 got 2900, these are loads it liked, I got some faster, but accuracy suffered...as most Ackley's I ever owned have. Being a tall man, I prefer longer barrels, 24" is about right, 22" feels like a carbine, and 26" just unnecessary for my style of hunting.
