I worked up accuracy loads in the 7 mag with 140g :
4064-3000 with cci 250 a must or hang fires
R#19 at 3250
IMR 4350
Big Game
New IMR Enduron powder equal to 4350
All shot tiny groups with the 140g Nosler ballistic tip and the 140g ttsx.
What my rifle likes maybe somewhat different than yours as bore dia is different, your lot# of powder is different, and your sizing dies are different.
I only worked with one powder at a time, cleaned the copper out every 20-30 shots, and there was copper in the barrel since velocity was 3200 and above with all powders other than IMR 4064.
Start with a rifle that has been bedded, barrel floated, trigger tweeked or you simply may not know what kinda results you get that will be repeatable. I did
have 140g Sierras blow up on shoulders of big deer, went to a 150 and 160g Sierra and fixed that problem post haste!
It has been stated before: Kiss the lands, find pressure on your load, then make adjustments to find best accuracy within 30 shots, darn quick.
ON another note,
A 280 bolt gun is dumb butt simple to load for with a 140g, bunch of powders. I shoot the 160g Nosler partition at 2930 fps with a load right out of the Nosler #4 manual, Rem 700 with a 24" barrel, IMR 7828, FEd 210(key).
Last edited by keith; 09/15/20.
