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 [email protected]

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.

I may give it a shot when this brass is done. I wish Lapua would make my life easy and just produce 300WSM.

I think im going to start at Hodgdon min and try again. I did manage to get a couple of sub moa 3 shot groups. I honestly think some of the other groups were me more than the loads. I typically have the range to myself but there were about 4 other shooters yesterday. Just didnt feel like I was shooting my best.

Heres a shot of the primers, 2 on the left are my loads, the one on the right is the factory load. A wise man on this site says flattened primers dont mean much as far as pressure is concerned. Outside of that, I didn't see anything else besides velocity that would indicate I was pushing it too hard. I stopped at 64gr(3k fps) Even then I only shot 1 round just to measure speed.

I



d really like to shoot the 62.6 loads again, first group of the day on a new rifle. SD/ES numbers looked alright, fell like it should have shot better. Other than that, nothing really seemed to jump out at me.

I wouldn’t worry so much about the flattened out primers as I’ve seen those with some factory loads, especially Hornady Superformance rounds. If the gun is a bolt gun check the brass for rings down low. Also are there any bolt lift issues? Those would be my main pressure concerns.

I definitely understand about the range. I quit going to public ranges a few years back. Now I pretty much only shoot at my hunting club range which is 300yds. If people are they before I’ll just go back to the camp and try another time.

Yes those are pretty flattened. Are all of those targets with 180 E-tips?? 62.8 looks really good.

I see it’s TTSX’s now. How long is your barrel? You’re getting some really good velocities compared to what the book shows.

Its 25in. Well, the rifle is Blaser R93 so no bolt lift but ive heard you can get the same effect with pressure as far as not being able to cycle the action. I had no issues with that. Mule Deer says flattened primes in of themselves mean nothing. Old wives tale I suppose.

I think I may reshoot a few of those. I just couldn't see to get settled behind the gun but had already made the trip to the range and just really wanted to get some chrono numbers. Our range is private but since its the only one around it has quite a few members. I usually avoid Saturday but it was busy week.

62.8 and 62.3 are on the menu. The first 2 shots velocity wise were close, it was the 3rd shot in both groups that opened them up. Could be me or something not lining up during reloading. My main concern being that these are only .050 off the lands is that I really dont want to seat them any deeper and push the pressure up. Its been my experience with Barnes that they may want to be out as far .90-100. Plan B is to start at the bottom of the book load and see what happens, although Id like to keep the velocity higher. I also have some 180 Nosler AB coming as well as 165 and 175 Barnes, 150 and 165 AB's on the shelf.

I agree with mule deer, I wouldn’t put much weight into the flattened primers.

To me the 62.8 load looks promising both velocity wise and grouping especially if you think you may have not shot your best group.

I’m not extremely familiar with the Hodgdon powders as I usually use IMR’s and reloader. Another option that will be similar to the 4350’s is RL-17. Although I couldn’t duplicate the accuracy of the IMR4350 a lot of people really like it for wsm calibers.

On another note, once you starting trying the AB’s and E-tips take a look at the Nosler book. They have load data on a bunch of different powders.

Ohh and I understand your concerns with wanting to keep the pressure down but I always load mine to the coal either the Barnes or Nosler book shows depending on the bullets I’m loading. I know a lot of people say to load monos close to the landings but actually seating them deeper has given me better accuracy. I have copied a pic of the same powder charge and same coal (Barnes recommended) just using TTSX’s instead of AB’s. Results were almost the same. Who knows maybe I flinched a hair.


https://i.imgur.com/xqxXI6y.jpg

I generally stick with H powders as I have big swings in my hunting temps so I typically stick with temp stable powders. I do have some reloader here though if all else fails.

Not going to try etips, just the AB's. Looking at the nosler book now. I think Barnes says to start .050 off and work further away. I factored my oal based off the readings from the oal tool. Still have a box of ttsx 180s to burn up.

I almost always run the cci 250 in my wsm's. They always seem to work well. Don't be afraid to go down to the 150 ttsx if you want to shoot ttsx's in your wsm. I've shot the 150 diagonally through a moose. Superformance will drive 150s at 3400 from a wsm and that's all the weight you need in a monolithic. The 150s are extremely accurate in my rifle. If you go lead core I like a 180 or even the 200g NAB.

Bb

I plan to have both a 180 and 150 load.....although I do have about 10 boxes of the 165gr TTSX sitting here.

Increasing primer brisance basically always improves temp stability on the low temp side, since the problem is fundamentally getting the powder lit.

Depending on the load lower brisance primer can work fine, but if I have to pick one that's not the direction I'm going to go for a hunting load.

CCI 250's for all .300 loads.

Makes sense

Im a CCI primer fan myself but in the magnum realm, the CCI seem to have the most reported issues and are the least recommended.

I have been using them for 25 years with zero issues. I used to use Winchester back in the day and did have a couple of misfires with those. Switched over to CCI and have had no issues.

Flattened primers do not mean much, but when the primers fall out after four loadings, it does mean the load is too hot for the brass.

I often load one piece of brass multiple times to test for primer pockets becoming loose.

Primer choice? I have never found any thing better than CCI 250s in 30-06 or larger capacity using 4350 or slower powders. I would start with H4831 in your WSM, and perhaps experiment with Accurate Magpro or Ramshot Magnum as they are very dense and you can get high charge weights without compression.

The slowest powders in the IMR Enduron line look promising, but I have no experience with them at this time.

Yep, I'd be looking at the 62.8 gr load and adjusting the oal a bit.... Maybe seat them a hair deeper...

Some really good information here. Thanks to all.

Yes sir, tired some of the more promising loads over again with the 1x fired brass, no flat primers or powder crunching. As I mentioned in an earlier post, the primer pockets were VERY tight on these to begin with. I assume that had to do with the flattening. The 1x fired brass was also easier to seat the primers this time.

I had palnned to try 4831 but due to the initial case capacity on the Norma brass being less than most brass,I wouldn't be able to get enough powder in to get to the velocity I was after without running compressed loads. Im pretty much sold on the Extreme pwders from Hodgdon. Ive had excellent results in all temps with it thus far.

Ive almost got the 62.8 load figured out. Actually 63.1 now. After using the 1x fired brass from my initial testing it seems the 63.1 got me back where I want to be.

Only had 4 shots on this one, target says 2.875 for COAL but the 62.8 load I pushed back to 2.850


Here is the x1 fired 62.8 and 63.1 loads, COAL back to 2.870(notice the velocity drop on .3gr more powder.....weird) the rest of the groups are different loads from trying the 180 NAB, which seemed to be easier to get to group. I took the 2 best 3 shot groups and went home and loaded up 5 rounds of those which are the 2 groups at the bottom left. I wasnt happy with those so I have 1 of each loaded up again to try later this week.



As it stands now, I have 2 180 TTSX loads( 5 rounds each) 63.1gr, one loaded 2.880 COAL and the other at 2.865
2 180 NAB loads,5 rounds, 61.9 and 62.5 again.

I use Federal magnum primers

Well, I think Im going to call it good, 63.1 180 TTSX, going to load 10 more and shoot them in 1 group. I suspect 8 out of 10 will be .7 and the others will push it to an 1in. I may mess with it a bit more later but Im going to start working on a 150gr load. Probably could have ended this sooner if I was only looking at 3 shot groups as there were many along the way that were sub .5. Even still, this load should work for any distance Id realistically shoot at game.

First 3 in 1 hole, pulled the 4th, almost go the 5th back in the same hole.

This is perfect. I might have to try some of your load data in my Sako!

In reality, I often wonder if my shooting or load prep may have caused some of the erratic groups that would have otherwise shown promise. Its one thing to have all the scattered, make me second guess myself when 2 go in 1 hole and the 3rd is an inch away. Especially if the chrono data says it was the same as the others.

For example, an identical load from yesterday, 63.1 but COAL 2890:




Here is the data from the Labradar on the above group

Looks like your rifle likes that TTSX a little farther off the lands unless maybe its you, like you said. That 63.1gr with the 2.875 COAL looks perfect to me. The variance is crazy low which is obviously really good. Are you allowing cool down time between shots? The barrels on every wsm I've ever owned heat up really quick.

I find it hard to shoot a "perfect" 5 round group. I have a Tikka 270wsm I can put 4 110gr TTSX's in the same hole at 100yds but for some reason that 5 one always ends up a 1/2" outside the rest. Very similar with the 300wsm I posted the pics of earlier in this thread.

The last 2 trips I took my temp gun. Fired one factory round to verify zero of the scope, took the temp and used that for the "cool down" temp. 67 the first day, 74 the next. After 5 shots i was at 110ish depending on where I pulled the temp. The chamber temp was cooler than part of the barrel I used for a baseline.

I have 10 empty cases left from my first 1x fired batch. Going to load them up at 2.875. Either shoot 2 5 round groups or shoot all 10 but let the barrel cool every 3 rounds.