250gr Gameking and 338wm

[Mad_Mikee]

I just purchased a new 338wm and I'm looking for some starting loads with the 250gr Gamekings.

In my other guns the Gamekings have held up well, are cheap to shoot and are very accurate.

I have a bunch of H4350 from my 30-06 so I'd like to find some loads that use H4350 powder and the 250gr. Gamekings.

If anyone has a Sierra loading manual, any starting point would be greatly appreciated.

 

[Lefty Dick]

Hit some on line data sources, any 250gr. data will list a decent start point for you.

Bullet make plays almost no bearing on the data, especially if you start low and work up.

 

[Johnn Peterson]

The Sierra 250gr Gameking (or 250gr SBT) is what I load for my son's 338WM. He's used them on game and is happy with the results, and the accuracy. I don't advocate anyone just go and use my particular load, even though it is about 3grs under maximum. I've loaded them for him using 65grs of IMR 4350 and a CCI 250 primer.

You've suggested using H4350 which is very close to the same burn rate as IMR 4350, and in the Seirra manual, using that bullet and H4350 Ext., their starting load is 59.2grs and the maximum is listed at 69grs. Start close to the suggested starting load or minimum and work your way up until you get the optimum accuracy and for me, that is usually at a grain or two below maximun.

 

[Mad_Mikee]

Thanks Johnn. That's the info I was looking for.

I usually start about half way between the book value min and max and work my way up in 0.5gr. increments.

Once I find something promising, I stick with that powder capacity and work on the OAL.

I've had a few people tell me to just use MatchKings for hunting but I'm still not 100% sold on that idea yet.

 

[Johnn Peterson]

Thanks Johnn. That's the info I was looking for.

I usually start about half way between the book value min and max and work my way up in 0.5gr. increments.

Once I find something promising, I stick with that powder capacity and work on the OAL.
I've had a few people tell me to just use MatchKings for hunting but I'm still not 100% sold on that idea yet.

You're quite welcome. I was going to scan the page and send it to you but you have the basis of info you wanted as is.

That's 'usually' where I start, minimising the freebore as much as possible, providing the cartridge fits in the magazine.

With input from a number of people like graylake, todbartell and in particular BC Sportsman, on a few of my main hunting rifles, I'm in the process of changing over to Barnes TTSX bullets. A little getting into step with todays technology. Going with Matchkings 'seems' a little questionable to me also but perhaps contact the Sierra tech department and see what their thoughts on that are.

Anyway, good luck with your load development and let me know how it turns out.