Home Forums Reloading Big Game Rifles Primers for 300WSM

About to start load workup on y 300WSM, I'll be using Norma brass and H4350 and H4831SC. I'll be trying most of the Barnes TTSX and Accubond offerings. My question comes down to primers. I have about 6k Federal Match Large rifle and about the same in CCI BR2. I have 0 Magnum primers.

Ive read a few posts on the matter but nothing really to sway me to invest in Magnum primers. Any thoughts to contradict just using the standard LR Match primers?

Id rather not burn bullets and powder jsut to try both primers. Perhaps the safe route is just to start with Magnums but if I can avoid it, I just as soon keep all my rifles on the same primer diet.

I use Winchester magnum primers in everything I load for.308Win,30-06,7mag,7STW,300WSM,300Win Mag,338-06.I got tired of switching back and forth between primers so I tried the magnums in my non magnum cartridges and found them to work quite well.I tried a standard large rifle primer in my 300WSM and it worked OK,but I really didn't see any advantage using them.The only time I ever had issues with using a standard large rifle primer was I was trying some starting loads in my 300 Win Mag with Reloader-22.I had a couple of rounds that failed to ignite the powder and a couple that gave me hang fires.I pulled the bullets on the ones that failed to fire and found the powder was blackend but none of it ignited.The hang fires were scary when you pull the trigger and there is a half second delay in going off.It could have been the double based powder was harder to ignite or the primers(CCI large rifle)primers were just going bad.I think the primers you have will be Ok for the H-4350 but with the H-4831,you might be better off using a magnum primer.

My favs...
Fed GM210M

I would only consider Federal 215 or 215 match for temp stability if I was planning to hunt it.

At temp do you think the magnum primer would work in which a standadrd primer wouldnt. Ive used the BR2 primers in single digits with no issues but that was also in conjunction with a smaller powder charge and case in a 6.5x55

As a general rule, I start with standard primers with cases from the .308 family and smaller. I start with magnum primers with anything in the WSM or belted mag families. I can go std or magnum with the '06 family, depends on the powder. Once started, I only change if something isn't working.

So for .300 WSM, I'd start with the Fed 215 magnum match primer.

There are no guarantees, all you can do is play the odds. IMHO you're more likely to be wasting powder and bullets NOT using the magnum primers than using them.

Tom

Had a good load with 4064 and 150 TTSX's. Used CCI-200's. With the slower powders, you're right on the edge of considering/needing a mag primer.

Well, local shop only had WLRM, guess they'll have to do.

Try both , and let your rifle tell you which it prefers.
My rifle and I are happy with F210M’s.

I tried Winchester standard large rifle primers and CCI magnum primers in my 300 WSM and found zero difference in accuracy or velocity. Since the 300 WSM was the only magnum rifle I owned at the time I just used the large rifle primers for everything.

I have used CCI regular and S&B regular primers for years and have not had any fail to light.

Well I might just have to try the standard primers. Apparently, the Norma brass primer pockets don't play well with the Winchester primers.

I got tired of trying to stock both large rifle primers and large Magnum rifle primers back when reloading supplys were so scarce so I started useing only CCI Magnum large rifle primers for all my .30 cal's from .308 Win up to .300 Win with no issues and have no plans to change now.....👍......Hb

I haven’t bought any new brass since the beginning of the Obama years when components were scarce, but I too had problems with Winchester primers “not playing well” in any of the new brass that I bought back then. They sat rather loose in the pockets of the brass of that time. Also had the same problem with Remington and Federal primers, all of which were a tad too small or the primer pockets were a bit too big, what ever the case may be.
The ONLY primers that I found to fit snug in any and all brass were CCI 200 and 250 M. So I have pretty much just stayed with those on every thing now.

A quick hit with a pocket uniformer and I got them to seat.

Next chapter in the saga. Using the Barnes data and cross referencing with a couple other sources, decided to start my load at 64.3 which is in the middle. Barnes says 67.1 for max and that would be compressed....but I'm already crunching powder at 64.3.

Only variance from the barnes load is they are using Rem brass and I'm using Norma. I get there could be a difference in capacity but I'm also seating my initial loads at 2.875 vs Barnes2.830

Also should note, Hodgdon is showing 63.7 as max with a 180gr E-tip and also a compressed load which seems to mirror where I'm at. Both companies using Win cases.

I use WLRM in everything as well. Multiple short Mag rifles and 7mm rm.

This is my recipe for my 300wsm. I always use Nosler Brass...


https://i.imgur.com/4zYr97m.jpg

Hit 2990 with 64 grains of H4350, I really don't think I want to go much higher than that. Had flat primers on all my loads. Not that it means much.

Re17 gave me more velocity , better accuracy, and less pressure sighns than H4350.
Might give it a try.

My hunting temps are anywhere from 5 to 100+ degrees. H4350 has proven to me to be very temp stable where the RL series for me has not.