Magnum Primers in the 7mm Rem Mag?

F

fw707

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Is there a general rule?

Sometimes?
Always?
Certain powders?
Loads over so many grains?

I've loaded a few rounds for a new rifle according to the Sierra manual specs. They don't specify mag or LR primers, so there's no mention of pressure differences between the 2 types.
 
Just because it is a magnum caliber that doesn't mean you HAVE to use a magnum primer.. Go with what your reloading manual recommends for the powder you want to use. Some powders require a hotter magnum primer, most don't.
 
Bear in mind that I don't use the 7 Rem Mag. Prior to a couple years ago, I would have said to use a standard first, and then if you need it move up to a magnum. Unless it is one of those powders that simply demand a magnum primer (H-870, IMR-5010, etc.). However, after a couple squib loads on the range on a particularly cold day in a .300 win mag, I would amend my opinion to include the use of magnum primers with any cartridge when the temperature is going to be below zero. If you are shooting BR and are worrying about that last few ten-thousandths of an inch, then you would have not asked the question anyway.
John
 
Originally Posted By: 2muchgunI would use a magnum primer with every round you load........

Me too, Been loading the 7 Mag since 78 and have always used them with great results.
 
My standard loads in Rem 700's-7 Mag-Rem brass in all loads

63.0g of IMR 4350, Rem 9 1/2, 150g Nosler or Sierra

65.5g of IMR 4350, Rem 9 1/2, 140g Nosler or 139g Hornady

72.0g of R#22 with a CCI-250, 120g Nosler

72-73g of R#25, Win Mag primer, 154g Hornady SST or Interbond

71.0g of Retumbo, Fed 215, 162g SST(Max load in my rifle)
 
Originally Posted By: 2muchgunBecause when you ignite a powder column of that size, you will experience more consistent ignition.......

Good point. I looked up 7 mag loads in my manuals, now that I'm home.. All used a mag primer, except one old Hogdons book..
 
It is good advice to work up your hunting ammo starting with the mag primer when you are burning this much powder. Hang out with the bench rest fools long enough and you will pick up some bad habits....
John
 
I experimented loading just large rifle primers in my 7 Mag once, about 1 in 5 shells ended up a hang firing on me. PffftBOOM they went!
 
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Originally Posted By: fw707Is there a general rule?

Sometimes?
Always?
Certain powders?
Loads over so many grains?

I've loaded a few rounds for a new rifle according to the Sierra manual specs. They don't specify mag or LR primers, so there's no mention of pressure differences between the 2 types.

Not so Grass Hopper,I am not trying to be a smart arse. But according to the Sierra manual they specified a FED. 215 Primer which is Federals Mag primer.
Look on the first page of the 7MM Rem.Mag. data it is there in black and white.
 
The problem is that "regular" and "magnum" have no specifications. Some "regular" primers are hotter than many "magnum" primers.

Jack
 
Thanks everybody for the replies and information.

I had a few of those hang fires last week a couple of you mentioned. I figured they had to be caused by the lack of fire from the CCI LR primers I was using.

Dab, the info is right there in the manual "in black and white" like you said. I read the body of the data page looking for primer specs, but I totally overlooked the part at the top of the page.

I've got 1k of the Winchester Mag primers so I'm good to go.
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