Thread: Large vs magnum rifle primer advice??

Hey team,
So I was reloading a few different calibers today and realised afterwards I had accidentally used magnum rifle primers instead of large rifle primers when I was loading my .260
I was wondering if this would make much of a difference... not sure if I have to pull them or not....
Appreciate any help
Cheers

some will say you need to reduce loads by 2grns....ALL my loads in poohseventy have magnum primers and IN MY RIFLE are a couple of grains above book max so if your rifle likes it hot..they SHOULD be fine. if they hot to begin with....maybe not so much.

I used to use them in my 260. Went to lr and didnt change a thing or notice anything

Originally Posted by Micky Duck

some will say you need to reduce loads by 2grns....ALL my loads in poohseventy have magnum primers and IN MY RIFLE are a couple of grains above book max so if your rifle likes it hot..they SHOULD be fine. if they hot to begin with....maybe not so much.

2 grains is heaps, or is that .2?

I use mag primers in most loads now never noticed a difference starting using them because of using heavy loads of slow burning powder

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Originally Posted by Gibo

I used to use them in my 260. Went to lr and didnt change a thing or notice anything

yep same here in a few medium cartridges with ball powder. Supposed to be about even ignition and lower ES

Thanks fellas,
It’s a fairly conservative load anyway, 42gn 2209 lrab 129gr through a Forbes rifle.
Have had hotter through it but opted for lesser load as didn’t seem to compromise accuracy.
Appreciate all your feedback, especially as is seems I won’t have to pull all my loads... and I only have anertia hammer!!
Any thing else welcomed. Cheers

The name magnum is a bit misleading. They produce a longer lasting ignition flame than standard primers which was found to be useful in getting the early double base ball powders used in military ammo to ignite consistently due to the burn rate retardent coating on the outside .
They are also good with the slow single base stick powders especially in very cold conditions.

Would be interesting to see if your zero remains unchanged, or point of impact has moved......

I have read that for a powder charge of 60 grains of powder or less use a standard LR primer and the magnum version for greater than 60 grains. There is a difference in pressure generated by the two with the magnum giving a bit more pressure.