Gunsmithing 300 WSM Question

[LRI]

This may be more applicable for the reloading section, but I'm interested in what other plumbers have to say about this.

Recently we got in a 300WSM built somewhere else. The owner has had a long series of problems with this rifle. 3+ year wait, "minute of pringles can lid" at 100, etc.

It's a Borden Action, Lilja Barreled, McMillan stocked piece. All good parts.


So, we get it and start dickering with the load. First time out it shot really well. Staggering in fact. After a little more discussion with the owner we discovered this:

That the builder encouraged him NOT to use magnum primers. He'd stated that magnum primers with ball powders doesn't work.

We shot it two ways with our hand loads. 4831 and RL19 (might have been RL20-Garrett did the load work)

In both instances we used Federal 215's and the gun shot well. It seemed to like the RL better, but both performed well.


So, my question: As a std practice, don't "magnum" cartridges go with magnum primers? (I'll admit to it being a little rhetorical, but I'm keeping an open mind)

I've not heard of this ball powder/stick powder distinction.

Input encouraged.

C.

 

[bohem]

Re: 300 WSM Question

Yes and no.

Tom Sarver has told me in no uncertain terms that unless I'm trying to light more than 85gr of powder at once, I should not be using a magnum primer.

My last 300WSM I ran with mags and non mags. The non-mags shot tighter with CCI primers and made no difference with Wolf primers.

Turns out that CCI puts more compound in the #250 (LR mag) than the #200 (regular LR). Wolf however just changes from a brass to a copper cup for a harder material to take "higher pressures".

With a compressed load I do see that the #250 mag primers seem to work a little tighter on my 7/300WSM but if I shoot an uncompressed "lower node" the #200's work just fine and I get way under 1/2 MOA with them either way.

I ran a bunch of surplus BLC-2 under 150gr surplus bullets in my 30-06 and with the surplus powder I found that more consistent ignition came from the #250's. I suspect that was a powder issue as opposed to anything else though. And machine gun ammo pull downs are not conducive to anything but blasting rocks so I wasn't chasing an accuracy point with that load.

If you want, shoot me a PM and we'll trade some info on the rifle, I can help you work up a load very quickly for it with several different powders and bullets to see what the rifle feels about them.

Hope that helps and I didn't just stir the mud puddle.

 

[BradfromND]

Re: 300 WSM Question

Ive heard the opposite....use magnum primers with ball powders for a more consistant burn. For me, if it's a magnum, it gets magnum primers. Of course it is cold up here too so it helps with ignition for hunting rifles.

 

[Sage Flats Shooter]

Re: 300 WSM Question

In my experience if it is a mag it gets a mag primer. I generally use the 63 grain mark as my limit with standard cartridges and standard primers +63 gr and a mag primer gets used. I have not had any ignition or accuracy issues getting 60 to 63 grains of powder in either my 280 AI or my 30-06 AI using standard primers.

Just my $.02

 

[LRI]

Re: 300 WSM Question

Fair enough.

I'd not heard of the std primer/magnum cartridge trick. As a defacto practice I've just stuck with mag/mag. It's seemed to work thus far.

Anywho's. . .

Thanks germs!

 

[jbell]

Re: 300 WSM Question

Im not a professional at this like others here but I would go with what has good accuracy and also gives good #s over the chrono and to hell with the rest. But then again Im just stating the obvious and not answering the question. I think it depends on powder volume and case design. So it may be more caliber specific than powder specific (even with magnums)

 

[E. Bryant]

Re: 300 WSM Question

It'd be really interesting to know a couple of things:

1) How well the customer's rifle shot with a good factory load;
2) The chrono velocities with the customer's hand loads, and with your handloads.

Certainly, a larger-than-expected distribution in velocities would be a possible symptom of inadequate ignition. If the velocity swings were bad enough to cause a couple inches' difference in POI at 100 yards, I'd think it'd be pretty damn obvious on the chrono.

I've yet to see a good hard-and-fast rule about when "standard" primers are to be used, and when "magnum" primers are required. I suspect is has to do with some combination of powder speed, powder weight, granule shape, and charge column geometry. My experience with reloading for magnum handgun cartridges taught me that if in doubt, err towards more ignition power

 

[excaliber]

Re: 300 WSM Question

What actually makes a cartridge a magnum? I used CCI 200 just because it made my ES better. I shot it in cold and hot weather with no failures.A 300 WSM is not actually a magnum. It is very efficient cartridge. I use magnum primers (cci250) for 70gr of H -4831 or similar burn rate, if the powder exceeds 90grs use Fed 215.

 

[Guest]

Re: 300 WSM Question

We just started using cci#200 primers. We have had some issues with the #250's.

4831SC is a great powder for this caliber.

 

[LRI]

Re: 300 WSM Question

As it applies in general terms, a "magnum" is a cartridge capable of developing over 3000fps.

least that's what I read once.

Not so applicable these days I guess.

 

[Dennis_in_VA]

Re: 300 WSM Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">As it applies in general terms, a "magnum" is a cartridge capable of developing over 3000fps.

least that's what I read once.

Not so applicable these days I guess. </div></div>

That means my .223 spitting out 55 grainers @ 3300 fps is a "Magnum" ?

I'm just sayin'

 

[oinco]

Re: 300 WSM Question

In researching vaguely similar questions awhile back-I ran across this qualitative primer "heat" chart below, and it seemed to echo what other shooters I am supposed to trust said....but I still use CCI BR2's in my .338 Edge, 300RUM, and some in 300wm. My 300wm does like the Federal 215's however. Go figure. I am probably doing everything else wrong too.

I did find some interesting videos of the flame patterns of primers iirc they were on youtube linked from the 6BR site?? No hard facts were gleaned by me- just interesting - although trying to accurately model flame front propagation does seem fun.