Which Primer for my .300 Win Mag Load?

[mdslammer]

Feenix,
Great chart! Thanks for sharing.

 

[FEENIX]

Feenix,
Great chart! Thanks for sharing.

Happy safe loading, cheers!

 

[DocB]

FEENIX YOU ROCK BUDDY!!

This is awesome and must have information!!

Thanks Buddy!!! YOU'RE 'DA MAN!!

DocB

 

[FEENIX]

FEENIX YOU ROCK BUDDY!!

This is awesome and must have information!!

Thanks Buddy!!! YOU'RE 'DA MAN!!

DocB

LL! I'm a sucker for quick references.

Cheers!

 

[tbrice23]

LL! I'm a sucker for quick references.

Cheers!

Feenix
I've recently got some loose primer pockets in my winchester 300wm brass and it seems WLRM primers fit more loosely than cci250 or f215m. Looking closer I've found WLR is smaller diameter than cci200 cci br2 f210m. Looks like the chart contradicts my findings. Dont know how old the chart is but maybe specs may have shifted slightly.
Does this sound right?

I'm considering getting a Hart Case Saver. I should start another thread on it to gather other's experience with it.

Well I might as well contribute it this thread. My new Bergara 300wm barrel likes Cci250 with h4831sc and f215m with h1000 all with 185 vldh.

 

[Lefty7mmstw]

Feenix
I've recently got some loose primer pockets in my winchester 300wm brass and it seems WLRM primers fit more loosely than cci250 or f215m. Looking closer I've found WLR is smaller diameter than cci200 cci br2 f210m. Looks like the chart contradicts my findings. Dont know how old the chart is but maybe specs may have shifted slightly.
Does this sound right?

I'm considering getting a Hart Case Saver. I should start another thread on it to gather other's experience with it.

Well I might as well contribute it this thread. My new Bergara 300wm barrel likes Cci250 with h4831sc and f215m with h1000 all with 185 vldh.

they are both large rifle, but there is a slight amount ( thou. or so) of tolerance in size with primers. Usually loose pockets= hot loads, especially if you aren't getting better than three firings before looseness.

 

[tbrice23]

They have 5 firings. But I do load them warm. I think 300wm shine on the higher velocity node.

 

[Lefty7mmstw]

They have 5 firings. But I do load them warm. I think 300wm shine on the higher velocity node.

I've been shooting 300win for twenty years here; yep they do like to run rather hard, but too much pressure still loosens things up after a spell. At the price (and availability) of components lately, I'm rather surprised people still load hot enough to work brass. There are lots of 30 cal's out there that'll do 300win ballistics loafing, so it really isn't worth it imo. I personally went to the 300rum for heavy pills and use my 300win for mid weight bullets.

 

[tbrice23]

Lefty
How many loads are you getting? In what brand of brass?

Also I square primer pockets and remember someone a long time ago saying that they believe reaming PP was to blame for loose PP. I don't think I agree, if it's done carefully. I'm with you on hot loads enlarging them.

 

[FEENIX]

Feenix
I've recently got some loose primer pockets in my winchester 300wm brass and it seems WLRM primers fit more loosely than cci250 or f215m. Looking closer I've found WLR is smaller diameter than cci200 cci br2 f210m. Looks like the chart contradicts my findings. Dont know how old the chart is but maybe specs may have shifted slightly.
Does this sound right?

I agree with ...

they are both large rifle, but there is a slight amount ( thou. or so) of tolerance in size with primers. Usually loose pockets= hot loads, especially if you aren't getting better than three firings before looseness.

It is not as tight of a tolerance as one would think or hope for, it's probably around a +/- .0015" range. Having said that, if you take the large rifle B diameter of the 6 on chart, it'll yield ...

.2097" min
.2112" avg/nominal
.2127" max

Most of my brass are Winchester and I get at least 5-6 firings without experiencing loose primers problem and regardless of primers used. I have all the primers on the chart but I prefer the CCIs (200, BR2, 250) for most of my LR loads.

 

[Lefty7mmstw]

Lefty
How many loads are you getting? In what brand of brass?

Also I square primer pockets and remember someone a long time ago saying that they believe reaming PP was to blame for loose PP. I don't think I agree, if it's done carefully. I'm with you on hot loads enlarging them.

I don't loose primer pockets on my current loads. I lost a couple of pockets on 270win test loads three or four years ago. I'll get case head separation or a cracked neck first.

I've gone to using a Lyman primer pocket uniforming tool lately with many of my cases (especially win as they are rather shallow) and it hasn't made a difference on pocket life.

 

[Caleb85]

I use GM215M in my 300 Sendero but I have a 7 mm Sendero that I found the best groups with winchester large rifle (non magnum)..

 

[Lefty7mmstw]

I use GM215M in my 300 Sendero but I have a 7 mm Sendero that I found the best groups with winchester large rifle (non magnum)..

the wlr is a heck of a primer for middle sized rounds where you don't want to go with a 215, 250 or wlrm. Remember though, the wlr isn't that mild of a primer as win designed it to light their Ball powder up in standard casings.

 

[tbrice23]

+1

I'm using WLR and 7828ssc in my Sendero 7mag with 168vld.