magnum primer question I am confused

[JHC-II]

Howdy,

Just started hand loading for the 300H&H here is the strange part. In my 7MM Rem Mag I use IMR4350 over a federal Large Rifle Mag primer. I use the Lyman bible and it says I should use a Large Rifle primer I am putting 4 more grains of IMR4350 in the H&H than in the 7mmRM am a little puzzeled with this am I looking at that much more of a pressure spike if I shove a mar primer in. I do live in a cold part of canada and use a magnum primer in some of my casings when it dips down below minus 25, however I am taking the H&H with me to Africa in the new year and if someone cold give me some clarity it would be greatly appreciated.

cheers

 

[Biggunners]

WOW - WOW - WOW ----STOP, RIGHT THERE - Two differenet things . TAKE - A - BREATH - READ THE INSTRUCTIONS - A wise man always said , read the instructions , SO read the instructions and proceed , PERIOD .

 

[Eagleye]

Howdy,

Just started hand loading for the 300H&H here is the strange part. In my 7MM Rem Mag I use IMR4350 over a federal Large Rifle Mag primer. I use the Lyman bible and it says I should use a Large Rifle primer I am putting 4 more grains of IMR4350 in the H&H than in the 7mmRM am a little puzzeled with this am I looking at that much more of a pressure spike if I shove a mar primer in. I do live in a cold part of canada and use a magnum primer in some of my casings when it dips down below minus 25, however I am taking the H&H with me to Africa in the new year and if someone cold give me some clarity it would be greatly appreciated.

cheers

If you are building a load for that 300 H&H, I am guessing that you are starting about 6% or so below and working up, right? If so, you should have no issues with that Magnum primer. Just start using it and keep using it. Seldom enough difference in a case that big to cause trouble. Just use safe load development practices, and use whichever primer you like. BTW, ignore the newbie post! Regards, Eagleye.

 

[JHC-II]

primer

yup going to disregard the noob comment.

According to the Lyman bible these are published numbers I am putting 61.0grains of IMR 4350 into a 7mm Rem Mag 175 grain also requiring a Lg R mag primer, where my confusion falls in the same manual it is say 64 grains of IMR 4350 Lg R primer into a 300 H&H with a 200 grain bullet. This is of course the top end of the spectrum and wonder why the use of a magnum primer in the 7mm RM and not in the 300 H&H. just seems logical magnum case more of the same powder would require the use of the same primer, any insight would be greatly appreciated.

cheers

 

[chappy]

for ease of reloading i use magnum primers in all my hunting loads. then i won't worry about cold weather issues. i also like to work my loads up in warm weather as sometimes a load worked to max in cold weather will be a little hot in the summer. just start at 5% from the top load and work up.

 

[RojamB21]

He's atleast more than half right and they are both different types of calibres and basic structure is also diffeerent , so use magnum primers for all magnum loads and drop 5% charge and start right there so you wouldn't be worrying cold weathers and if you are going to hot hot country, in my understanding you don't need magnum primers.There is no harm reading the instructions and following them precisely

WOW - WOW - WOW ----STOP, RIGHT THERE - Two differenet things . TAKE - A - BREATH - READ THE INSTRUCTIONS - A wise man always said , read the instructions , SO read the instructions and proceed , PERIOD .

 

[Ganderite]

4350 is not difficult to ignite, so a standard primer would work just fine. For cold weather, a magnum would be better.

The Winchester primer is designed to work with ball powder and is hotter than CCI or federal. It is a good compromise.

Africa and winter hunting are two extremes (although Africa is not really hotter than our summers here) so it is appropriate to make ammo for that application.

If you are testing your Africa ammo here, store the rounds in your shirt pocket, before you shoot. That keeps it at a toasty 98 degrees.

For both applications, cycle all the rounds through your magazine and chamber, to make sure they all chamber smoothly. Visually inspect all primers to make sure non are upside down.

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