Re: .338 win mag problems
I wouldn't change your powder at all, If you have not all ready done so trim your primer pockets all to the same depth, and if you can mic all of your brass to see if there is alot of neck thickness variations, to sort the good form the bad so that you can have cosistant, and straight loads.
however a good resipe "might"
I love Sierra game kings @ 250gr. with the right ammount of RL 19, gave me my best results.
The 338 win. is by far my number one pick for hunting here in Alaksa
Faris in Fairbanks.