switching regular recipes to magnum primers?

I worked up a load with 760 for my 7-08 with mag primers in late 80's, been using that ever since. My one note on using them in place of std's is that you should work the load up again, if you are near max, cut the charge a bit before trying, and don't expect it to shoot the same. I recently saw an article I wish I'd bookmarked, as they pressure tested various primers, think it was 4 brands, on something like a 308 or -06 sized case, and std's were running about 4000, mags ran 7-8000psi, just the bare primer in the case in that test. I've noted that there are times when mags produce krappy SD's too, and a std won't.
 
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Well, I humbly stand corrected. I have finally found the article that explains the real difference between normal and magnum primers at CCI anyhow. Because there is a difference. It's probably safe to say that other brands of primers use the same method too.

For those who really care to know, please read https://www.accurateshooter.com/technical-articles/primers-what-you-need-to-know/ and the associated article written by Allan Jones, ex-manager of technical publications for CCI Ammunition and Speer Bullets at:

https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079#replay

Almost everything is on the Internet. You just have to be able to find it!
 
good info tfs

for what its worth, had interesting results switching primers in 308 w/168 gr pills
CCI 200 LR gave ~60fps less velocity than CCI 350 LPM with the same powder charge
 
I tried CCI 200 vs CCI 250 magnum primers in 6.5 Creed, 308 Win & 7mm Rem Mag with 5 different powders, shot in 3 different temperatures

Results :

6.5cm
-15c Avg Speed / SD
CCI 200 2599 fps SD14
CCI 250 MAG 2609 fps SD27

+13c
CCI 200 2592 fps SD18
CCI 250 MAG 2592 fps SD19

+29c
CCI 200 2623 fps SD18
CCI 250 MAG 2629 fps SD18
 
308 Win

-15c Avg Speed / SD
CCI 200 2448 fps SD17
CCI 250 MAG 2465 fps SD17

+13c
CCI 200 2429 fps SD12
CCI 250 MAG 2443 fps SD17

+29c
CCI 200 2458 fps SD14
CCI 250 MAG 2471 fps SD11
 
7mm Rem Mag

-15c Avg Speed / SD
CCI 200 2761 fps SD16
CCI 250 MAG 2784 fps SD26

+13c
CCI 200 2774 fps SD11
CCI 250 MAG 2771 fps SD13

+29c
CCI 200 2834 fps SD13
CCI 250 MAG 2830 fps SD10
 
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