Got my Cadex .300 PRC - standard primers or magnum?

[precision.riflecraft]

Hi everyone, finally got my Cadex .300 PRC. Here it is next to my Savage .308. So for .300 PRC... Standard primers... or magnum?

Several precision shooters experienced in load development for .300 PRC have advised me that standard CCI 200 primers produce lower ES than comparable magnum primers in this cartridge, so I stocked up on the BR-2, reasoning that it's a match version of the 200 treated to more QC, or so I've been told.

Then I came across a discussion of cold weather and was warned that standard primers in magnum cartridges can cause sub-optimal ignition in very cold temperatures. It bears mentioning that I'm in Canada, but apparently this is more of an issue with ball powders.

I'll be doing my load development with H1000, which of course is extruded. One of the reasons I favor Hodgdon's Extreme-series powders is their relative temperature insensitivity, so there's that.

What do you guys think? Should I hold out for magnum primers or steam ahead with the BR-2s?

 

[SKWERLZ]

I got a better ES with #200 in my 338 edge over the #250’s
If you’re running a ball powder in really cold conditions magnum primers could be preferable

 

[precision.riflecraft]

I got a better ES with #200 in my 338 edge over the #250’s
If you’re running a ball powder in really cold conditions magnum primers could be preferable

I do wonder at what temperature it becomes preferable with H1000. It can get pretty cold up here.

 

[Dgd6mm]

Magnum

 

[SKWERLZ]

I do wonder at what temperature it becomes preferable with H1000. It can get pretty cold up here.

I’ve read 20F and below is a good excuse for a magnum primer regardless of ball or stick powder.

 

[moondog]

H-1000 BR2s, CCI 200s 210M gave me the best accuracy at distance. Mag primers never did well for me over 2 barrels. Don't really shoot mine below 30°

 

[762plinker]

bottom line ya gotta test in your combinations...

 

[No i deer]

A few fps is irrelevant so I'd go with the magnums to be on the safe side..

 

[284winner]

I see zero difference mags vs standard LR primers in my 300s. If I had a 300 NM, I'd probably go with the mags. The extra powder IMO makes it necessary for using LMR primers for ignition to be consistent. To be clear, magnum primers are made for magnum cartridges. There IS a fine line with certain magnum cartridges where both can be used.

 

[Dgd6mm]

I see zero difference mags vs standard LR primers in my 300s. If I had a 300 NM, I'd probably go with the mags. The extra powder IMO makes it necessary for using LMR primers for ignition to be consistent. To be clear, magnum primers are made for magnum cartridges. There IS a fine line with certain magnum cartridges where both can be used.

Yes!

 

[kev77]

Mag primer are more favorable here in Canada for the big 300's. 215s, 250s, S+B mags. All shot more consistent at distance then standard primers I'm my 300 Normas.