Magnum primers in non-magnum loads

[blixen]

This has probably been answered before, but I couldn't find it.
I got a couple boxes of magnum large rifle primers in with some other components.
Is it a bad or unsafe idea to use them in the place of regular large rifle primers? I can see where they would affect the load data. I shoot mostly light loads--like 16 grains of 2400 in 30-06 and 30 Krag.

[MattOrgan]

In my area the only primers that were available until recently were magnum types. I have substituted them with no apparent problems in cast bullet rifle loads. None of my loads are even close to maximum and use powders that include 2400, 4759, Red Dot, Bullseye, and Unique. I saw no difference in accuracy and velocity over my chronograph. The only change I've seen is more uniform velocities. This may be the lot of Federal large rifle magnum primers I'm using, or maybe the longer flame duration is more uniformly igniting the small amount of powder in large rifle cases. I'm not really sure.I substitute them in standard pressure handgun loads without issues. In most of my high velocity handgun loads I was using magnum primers anyway. The only change I've made is when loading jacketed rifle ammunition using magnum primers; I started my load development from scratch for a couple of them because they were maximum in the first place. I guess this distills down to the common safety practice of working up any load when changing any component or using a new lot of any component. I only follow this rule with maximum charges where I'm substituting magnum primers in rifle cartridges that I formerly used standard primers.
I don't recommend this to anyone else, if you are in doubt, start from scratch, watch for high pressure signs (not primer appearance) , compare chronograph results.

[ButterNutZ]

I ran magnum primers instead of standard in 308, 7.62x54 and 7.5 swiss with no problems. They were loaded either with Varget, CFE223 or IMR8208xbr. Also did the same with 9mm and 357, did not notice any difference.

[blixen]

Thanks,
I'll just use them up.

[GabbyM]

Case length plays a factor. 30-06 is a nice long case and many people use mag primers to light off slow ball powder like WW760.
Will even be listed in some of the manuals. With a smaller case size you'll get a greater deviation in initial primer blast intensity. since you have less volume for the blast to expand into. Also Rem mag primers are less strong than some other brands. So they aren't all equal.

[375RUGER]

I've used lots of magnum primers in non-magnum loads, but I worked those loads up with the magnum primers.

[oldpapps]

'MAGNUM' primers are not magnum in size but energies (amount and duration of flame expelled when ignited).
Some propellants are hard to get started. Other loadings are very loosely packed, some need fillers, and others are packed in, called compressed. They type of powder and or how tight or loose it is packed may require more to get going, thus magnum primers.

Substituting magnum for standard may cause a slight increase in pressure/velocity. Unless your load is 'on the edge', this is normally not a problem. For safety, reduce your starting charge a little and work up again.

Your loading of 2400 will not likely be effected much.

Always error on the side of safety,

OSOK

[Down South]

I would back off the load a tad and work back up, just sayin.

[blixen]

Message received. I usually shoot light loads anyway, 14-16 gr. of 2400 in a large military case, for instance.
Thanks.

[blixen]

Message received. I usually shoot light loads anyway, 14-16 gr. of 2400 in a large military case, for instance.
Thanks.