WSM Primers

[Trapper7]

I bought a raffle ticket at a banquet and won a Tikka rifle in 300 WSM caliber. Can anyone tell me if I need to use magnum primers or would the regular Remington 9 1/2 primer that I use on my 06 work?

I don't own any magnum rifles, so I'm not familiar with them. I notice the WSM isn't a belted magnum like the 300 Win Mag.

[Adam Helmer]

Trapper7,

CONGRADULATIONS on your winning ticket!

I am not sure about the proper primer for the 300WSM; I suggest you get hold of current loading data and be guided accordingly. You may be able to Google Hornady or Sierra, etc., and printout reloading data for your rifle.

I also noticed the new magnums have no belt and the fact seems to be they were never needed from the get go for the 7mm RM and others. Lack of a belt makes for easier handloading. I load my 7mm RM by backing off my sizing die and size to the shoulder for longer case life.

Adam

[Jack]

Congratulations on winning the raffle.
A current reloading manual will be the authoritative source on which primer-standard or magnum- you should use.
For myself, I tend to switch to magnum primers for hunting loads when the powder charge is at or near 60 grains of powder. Anything less than that, I use a standard primer.
What that works out to, in real life, is that cartidges that are based on the 30-06 case, like 270, 280, and 30-06, I'll often use a magnum primer. For a magnum cartidge, I would usually use a magnum primer.

[Rocky Raab]

The standard 9 1/2 is a pretty mild primer, but it should be adequate for most loads, especially loads using extruded powder.

Magnum primers are called for when any one of these things is true:

The extruded powder charge is more than 60 grains, or

The spherical/ball powder charge is more than 40 grains, or

The temperature is lower than freezing.


If in doubt, use the magnums, but do NOT switch TO magnums if the load is already near maximum. Back the load off by 5% of the charge weight first.

[Trapper7]

I spoke to another person this morning who owns & loads for his 300 WSM. He said definitely to use the magnum primers.