Tested recent available Argentina SP Primers. IMO they are as good as others if not better.
Caliber: 357Mag 18.5" Carbine Rifle
Brass: Starline new sized and trimmed to length
Bullet: Nosler HP 158 grain
Power: Ramshot True Blue @ suggested starting weight of 8.5 grains...
I have never been able to get LG to do as well as 296 until resently developing 125 grn loads for the 357 magnum carbine. I still prefer 296 for mag handgun loads for carbine for 140 grn and heavier bullets.
!!! RIFLE/CARBINE only!!!
(Frame cutting may result with slower powders in revolvers...