large rife magnum primers vs large rifle primers

wildfin · Dec 21, 2023

I have been using the magnum primer in my 270 win and in my 300 win and I am wondering what the difference is between the 2 primers, and should I not use them in my 270. I have been using the magnum primer in the 270 for several years.

elkantlers · Dec 21, 2023

You can use them in a 270 no problem.
I like to use them when my charge is above 55 grains. or when you will be hunting in very cold temps.

I have used them in my 6.5x284 and 30-06. I've also used standard LR primers in each. As long as you work up a load with which ever primer you decide to use it will be fine.

wildfin · Dec 21, 2023

thankyou elkantler

257Tony · Dec 21, 2023

Yep, either will work fine. The old rule was over 60 grains, use a magnum primer. Some cartridges work fine with either, 270 is one of them.

Homer · Dec 21, 2023

When the war starts.......large pistol primers work too.....

littlebighorn · Dec 21, 2023

Changing from one to another will likely cause a bump/decline in MV depending on which you use. Even changing from one brand to another can make a big difference. Playing with different primers is one way some obsessive shooters fine tune their loads, especially when they are trying to get lower extreme spread in velocity.
I've also heard some shooters reporting that using magnum powders with slow burning powder can give a better burn rates, even with smaller cartridges.

Bluehair · Dec 22, 2023

Some powder manufacturers also recommend magnums for certain powders, such as some ball powders. Most of the manuals reflect this.

HikeHunt61 · Dec 22, 2023

Agree on all above. I did have some loads in a 280 that shot well with magnums, but when the ambient temperature was over 75, the pressures rose to the point the cases were sticking and the primers were flattening. Switching to standards stopped that problem, but the loads did not shoot as well.

In the end- it's totally load dependent- along with all the variables that come with it.