I have been browsing the little bit of published data there is for the 300WSM and was surprised to see that some call for the use of Mag primers and others standard. I would have thought it would be dtermined by the case capacity and the burn rate of the powder of choice. Is it that simple, if not what variables affect the choice? If we want to discuss one powder lets go with H4350.

Dave,
Yeah, the primer thing seems to be confusing at first. However, it is not as complicated as one might think.
First, the type of primer that one uses mostly depends on the powder. Stick powders, of which 4350 is one, are much easier to ignite than ball powders. Ball powders are also harder to ignite when they are cold. Hence, the recommendation for a magnum primer.
The other factor is the quantity of powder. The .300 WSM doesn't use a lot of powder so this is not a factor.
I personally would try standard primers like the Federal 210. I have had great luck with this primer and use it in my .375 H&H when using 4350.
I generally only use stick or tubular powders in my larger bores (above .224). I use some ball powders in my .22 K Hornet and my .222 Remington. I use Rem 7 1/2 Bench rest primers in these.
After you have worked up a load using standard primers you can back off a couple of grains and substitute a mag primer and work back up to see if you get any accuracy advantage.
If you have or have access to a chronograph, check your loads for consistency with standard primers and then try magnums to see if it helps.
Good luck in your reloading. Hope this helps.
The Bearman

For the most part I use mag primer in mag cases and std. primers in 06 size cases and std. primers always in the 9.3x64...

As long as I get the accuracy and velocity, thats all that counts.

Depends on the gun, they differ greatly in there likes and dislikes.

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

ve found that Winchester WLR primers work well with the 6 powders I tried...

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http://stevespages.com/page8.htm

I use mag primers almost exclusively in my handguns, but I use "bulkier" powders HS-6, H-110. I'm loading 38/357, 45, 44 magnum. All large cases, large bullets. Using one primer eliminates a variable.

I use a standard primer in the rifles. I load 223 and 223 AI. Ball powders. Changing back and forth from one type of primer to another introduces a variable in the data.

But I shoot in temperate climate and don't push the loads out to the ragged edge.

Thanks, all. I have some Big Game ready to roll with CCI-M and Fed 215Ms and some H4350 that will be touched off by the CCIs. I will try the H4350 with some Fed 210M s all this will be under 130 grain Barnes XLCs in Win. nickle 2.10" cases. I was curious though Steve/ricciardelli how did Varget/WLR combo do for you with projectiles 150 grains and under in weight?