Magnum Primers.

ShadeTree

Handloader
Mar 6, 2017
2,904
1,581
The one posters question on JD's 308 topic kind of peaked my interest. I know when using magnum primers you would want to back off some and work up and find out what works best and stays under pressure. I've no concern in that regard about using them.

But is there a known difference in either heat or the overall consistency with different brands of magnum primers? I got plenty so I'm fixing to do some experimenting on some loads with some.

Got CCI 250's and Federal 215's. I thought I remembered reading somewhere that Federal and Winchester were the hottest primers, and the CCI's were middle of the road. Any truth in that statement that you know of?

I'm figuring on testing in a 348 with IMR 4350 to start as that might be a good combination but might do some testing in 30-06 with them as well. Don't need to, but at some point down the road magnum primers might be what I'm left with, might as well figure out what works ahead of time . Just wondering if there's anything I should look out for between the 2 for those with experience with the mag primers?
 

SJB358

Ballistician
Dec 24, 2006
31,398
757
ST, don't hold me to this, but CCI250's were the hottest Magnum primer going when I last checked. They were middle of the road 20 years ago or more but I think they've swapped positions.

I may be full of hot water though but I did chrono the Fed 215M's and CCI250's in my 7 Mashburn and 338 Win and the 250's were always faster with the load being the exact with all other components.
 

ShadeTree

Handloader
Mar 6, 2017
2,904
1,581
ST, don't hold me to this, but CCI250's were the hottest Magnum primer going when I last checked. They were middle of the road 20 years ago or more but I think they've swapped positions.

I may be full of hot water though but I did chrono the Fed 215M's and CCI250's in my 7 Mashburn and 338 Win and the 250's were always faster with the load being the exact with all other components.

That's good info Scotty, thank you. That's what I was looking for. I got a lot more Federal 215's than the CCI 250's, but I was figuring on starting out with the CCI's.

I'll take your info about CCI's and start out probably a grain lower than what I was figuring, just to be on the safe side to get a baseline to work up from. Thanks again.
 

SJB358

Ballistician
Dec 24, 2006
31,398
757
I think you'll be fine. I think Mike always suggested backing off 5% if you're using a standard LR primer and going to a Magnum. I still think that is great advice myself.

I have swapped from 215 to 250's and vice versa without reducing, but I wasn't pushing it awfully hard on the load either. We are our own safety officers with this stuff.
 

ShadeTree

Handloader
Mar 6, 2017
2,904
1,581
I think you'll be fine. I think Mike always suggested backing off 5% if you're using a standard LR primer and going to a Magnum. I still think that is great advice myself.

I have swapped from 215 to 250's and vice versa without reducing, but I wasn't pushing it awfully hard on the load either. We are our own safety officers with this stuff.

I hit 2600 easy with no issues with Varget and the 200 Hornady FP's when doing my initial work up in the 348 with standard primers, I think that was around 57.5 gr's if I remember correctly. I ended up backing off about a grain from that for my regular load.

I have it in my head that if I was going to IMR 4350 with that bullet it would likely be at least 62-63 grains before I'd be up in the 2500's. Maybe I'm wrong. Speeds of lower to mid 2500's should be very suitable pressures with the slower 4350 compared to Varget.

Based on your info I'm thinking I'd start at like 57.5 with IMR 4350 and the CCI mag primer to give me a base line to jump up from there. That should start me in the lower 1/3 of where I'd end up. Maybe it will be faster than I'm figuring, maybe slower, but that charge weight to start shouldn't be in dangerous territory either way if I'm figuring right. Just got to do my calculations best I can and double check, then jump in and start. Ha.
 

xphunter

Handloader
Sep 15, 2005
542
868
Backing off as mentioned is very wise, and you get more trigger time to boot!
As a general rule, any time you change a component to a different brand (This includes different lots of the very same product...whatever component you would use for loading), pay attention not only to pressure changes, but also to POI and accuracy.
 

AFG270

Handloader
Aug 26, 2013
872
220
I have never compared different brands of magnum primers, but I have compared standard and BR2 to magnum primers. I usually back off about 2 grs then work up again.

The results from comparing standard to magnum are interesting, I've done it in 4 different rifles. The only change was the primer. The case, bullet, powder and powder charge and the seating depth were all the same.

The two reasons I did this are, first, I was getting low on BR2 primers for my 280 Rem and 25-06 and second, Hammer bullets recommends using magnum primers with most cartridges for their bullets and since I'm old and set in my ways, I did some of both to see if there was any difference.

280 Rem with 160g Partition over RL26.
Changed from BR2 to CCI 250
CCI 250 averaged about 20 fps more velocity and had a lower SD.

25-06 with 115g Ballistic tips over RL26
Changed from BR2 to CCI 250
BR2 averaged about 50 fps more, but the had a higher SD.

243 Win with 80g Hammer hunters over StaBall.
Tried both BR2 and WLRM
BR2 averaged over 100 fps more, but also had a higher SD

22-250 with 64g Hammer hunters over StaBall
Tried both CCI 200 standard LR and CCI 250 LRM
Velocity was about the same, LRM had a lower SD.

The Standard Deviation and ES were all lower using mag primers in all the rifles.

Accuracy was only compared in the 280 and 25-06 and was better in the 25-06 and about the same in the 280.

ShadeTree, I look forward to seeing your comparison of different brands of magnum primers.
 

wvbuckbuster

Handloader
Nov 5, 2015
1,501
609
My use of magnum primers has been to develop the load from the start using magnum primers. Never had any problems even with powder wts under 60grs. I found that using the CCI450 magnum in my 6BRNorma handled more pressure than standard match primers. Don't see any reason for a problem to reduce your load a grain or so when switching to a magnum primer. For what it's worth I've used magnum primers in 223,6BR,243,25-06,270,308,30-06,7mmRM 35Rem and 35 Whelen. Dan.
 

RL338

Handloader
Mar 23, 2017
912
935
According to an urban legion , Roy Weatherby bringing the 378 Weatherby to market is what brought the development of the magnum large rifle primer. Prior to that belted magnum cartridges were loaded with large rifle primers.
If you develop a load with a said primer stick with it and you should be fine.
 

jimbires

Handloader
Aug 16, 2011
2,502
474
@AFG270 , nice write up , and great info , thanks for sharing .


this is one thing I've never did any testing . I grab mag primers for large powder charges , and std primers for lower powder charges . when I first started reloading I used Win primers . these were marketed as being suitable for both . I never had a problem using them in everything .

I've read the difference between a match primer , and a standard primer , is the assembly man . only the more experienced worker can assemble match primers .

P5080091.JPG
 

ShadeTree

Handloader
Mar 6, 2017
2,904
1,581
AFG270, good info and not just a 1 off result. Your post reminded me that I seen the exact same thing using a very reduced load with Unique just a month or so ago.

Worked up the load with mag primers, then just to see what, or if any difference once I settled on the load, I switched to standard primers. Standard primers with the same load was substantially faster. Thought my chrono was lying to me, so tested back to back 2 more times magnum verses standard........each time the standard primer was a good bit faster.

The only thing I could make of it was that although it's happening in a millisecond, the standard primer was allowing a longer burn curve of the powder, developing more speed, instead of lighting off the whole charge in one instantaneous boom.

That might be complete hogwash but the only thing I could think of.

I would think if a person tried it, there would be a tipping point somewhere up the scale of charge weights. Where because of a more efficient & complete powder burn the magnum primer would produce more speed. Again, could be complete hogwash, but my brain says if the charge gets large enough the magnum primer would take over.

Interesting results regardless that in several cartridges you tried it in, the standard primer was faster. What I seen, but I figured that was a 1 off anomaly. Now I'm thinking maybe not?
 

Guy Miner

Master Loader
Apr 6, 2006
16,763
1,756
I'm pretty much out of Federal 215 magnum primers - only have a few left.

But I've got a thousand CCI magnum primers. :) I don't go through them real fast, so that should last me a good long while.

Regards, Guy
 

ShadeTree

Handloader
Mar 6, 2017
2,904
1,581
I’m pretty sure I posted this for you in another thread, but I think it has what you are looking for.

http://castingstuff.com/primer_testing_reference.htm

Don't think you posted it for me, but maybe you did.......my forgetter works pretty good sometimes. Now that you posted it, I do remember commenting on it. I believe at the time I was more impressed with the homemade tool that was used for measuring the power levels. Regardless it's good info to have. Thanks!
 

Joec7651

Handloader
Apr 7, 2019
583
307
Here is a visual comparison of various primers.
 

Slimfinn

Handloader
Nov 28, 2018
724
399
I do remember coming across an article a while back and from an individual in the primer industry, and written many years ago. It talked about at the time that WLR were the hotter of the large rifle primers, but may have been more associated with the lot to lot like differences (similar to potential differences between powder lots) and not the fact that Winchester was purposely out to manufacture the hottest primer. Did a quick search for the article will look again later


Found it, good info, I was a bit off in my recollection
 
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Cleveland48

Handloader
Jul 28, 2015
1,939
65
My use of magnum primers has been to develop the load from the start using magnum primers. Never had any problems even with powder wts under 60grs. I found that using the CCI450 magnum in my 6BRNorma handled more pressure than standard match primers. Don't see any reason for a problem to reduce your load a grain or so when switching to a magnum primer. For what it's worth I've used magnum primers in 223,6BR,243,25-06,270,308,30-06,7mmRM 35Rem and 35 Whelen. Dan.
I’ve always used the Cci 450 primers in my small primer 6.5 CM brass. Always had great luck with them having very low standard deviations.
 

Cleveland48

Handloader
Jul 28, 2015
1,939
65
I'm pretty much out of Federal 215 magnum primers - only have a few left.

But I've got a thousand CCI magnum primers. :) I don't go through them real fast, so that should last me a good long while.

Regards, Guy
Guy I’ve had great luck with the Cci magnum LR primers in both of my 416’s. Which I’ve never used the Winchester or federal. All the local places near me always stocked Cci, so that’s pretty much all I’ve ever used.
 

Joec7651

Handloader
Apr 7, 2019
583
307
I do remember coming across an article a while back and from an individual in the primer industry, and written many years ago. It talked about at the time that WLR were the hotter of the large rifle primers, but may have been more associated with the lot to lot like differences (similar to potential differences between powder lots) and not the fact that Winchester was purposely out to manufacture the hottest primer. Did a quick search for the article will look again later


Found it, good info, I was a bit off in my recollection
Thanks for posting this. Great information.
 
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