Mag primers vs large rifle primers

[williaada]

I have been reloading for a year or so, and have come across a few people who use magnum primers instead of large rifle primers. What is the pros and cons of using magnum primers on large rifle loads?

 

[Wrench]

Potential minor pressure increase. Mag excels with ball powder yet may decrease accuracy....or increase. If you have em'......run em.

 

[CApighunter]

I use them in any case with burning 60 gr or more powder. Have had nothing but good results, helped drop ES in my 280ai.

 

[rifletuner]

Very short form answer. Essentially a magnum primer burns with more intensity than a standard LR primer. They are intended for use in a larger case burning more powder (generally known as magnum cartridges, but not always).

If you use a standard LR primer in a magnum case you MAY get inconstant ignition of the powder. In this instance switching to a magnum primer SHOULD give more consistent ignition of the powder.

Using a magnum primer in place of a standard primer MAY adversely effect accuracy, but you would generally need a very accurate rifle to see a difference.

I am currently using mag rifle primers in some standard hunting cartridges that I would normally just use standard primers in. I happen to have about 10,000 mag LR primers on hand, and only about 1,000 standard LR primers on hand. So just using up whats easily available, and proven to work okay on target for me.

 

[eoperator]

A local reloading guru told me "use lrp for fast for cartridge/bullet powders and lrmp with slow for cartridge/bullet powders

 

[Downeaster]

To throw another wrinkle in there, Winchester LRPs are supposedly not far off a magnum primer.
Ive always used them in everything from 375 Ruger on down with great effect.