I sighted in a new Savage AR in 224 Valkyrie last week. Shot factory 60 and 90 gr factory loads during sight-in
The 90gr in that gun shot way better than the 60gr. It was a 7 twist and the 60gr had extremely high ES like 150fps which may have been the issue. They were 2.5 inch groups at 100 but the 90 gr hovered around .75 to MOA at 100.
Just a guess but might be that around here at low elevations the bullets may be stable while it warm but not when it get really cold?
Talked to my AR gunsmith who is in Minnesota and he said he was seeing stability issues with 90 so he has Shilen making him a large batch of 6.5 twist Rachet barrels. I have a cheap barreled 223 complete Upper I traded for so I am sending it to him for a custom barrel replacement and decided to go Valkyrie.
Bad side for now is all brass is Federal and hard to find. The factory rounds I fired and reloaded already seemed to have loose primer pockets..... typical of Federal brass. Will be shopping for some other source for sure.
I loaded 75 gr Amax in the factory empties so will see how that works.
"Anyone taking up handloading necessarily plays with unknown factors and takes chances. But so does anyone who drives a car,goes to a cocktail party,eats in a restaurant,or gets married."
Jack O'Connor 1963