Using regular or match grade (bench rest) large rifle primers in magnum cartridges.,

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pacobillie

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Assuming that I will not be using ball powder, or shooting in extremely cold temperatures, are there detriments to using regular or bench rest large rifle primers (as opposed to LR Magnum primers) in magnum cartridges such as 300 H&H and 300 Win Mag?

The powders that I plan on using include H4831SC, AA4350, N560 and IMR7828SSC, all of which are extruded stick powders.
 
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In certain loads I've found standard LR primers to give superior consistency compared to magnum primers, in cold weather (-15c). I now test both head to head in the individual application to see which will work best. I am 1/3 through a fairly thorough test of standard vs magnum primer in 223, 6.5cm, 7mm mag and 308. When I am done later this summer I will be able to share my results here on CGN
 
pacobillie said:
Assuming that I will not be using ball powder, or shooting in extremely cold temperatures, are there detriments to using regular or match grade large rifle primers (as opposed to LRM primers) in magnum cartridges such as 300 H&H and 300 Win Mag?

The powders that I plan on using include H4831SC, AA4350, N560 and IMR7828SSC, all of which are extruded stick powders.
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I would try the standard Federal match. It is quite hot.
 
It is generally accepted that if you are using more than 60 grains of powder that a magnum primer is best.
Match grade primers are made to tighter tolerances than regular primers, other than that, I do not believe that there is any other difference.
Yes, different brands of primers are hotter than others; Federal 215 being the hottest magnum primers (used by Norma in manufacturing Weatherby ammunition).
You will want to try the various primers to determine the best load for your hand loaded cartridge and rifle. But work your loads back up to max with each change of primer brand as it will change your powder burn and pressure spike characteristics.
 
Is there a reason that you would want to not use a magnum primer in a magnum cartridge?
They're the same price so wondering if there is something else.
 
cr5 said:
Is there a reason that you would want to not use a magnum primer in a magnum cartridge?
They're the same price so wondering if there is something else.
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I know that they are similarly priced. Just looking to optimize velocity and accuracy. I read that for "reasonable magnums" you might actually get more speed and consistency out of standard (power) primers. Btw, this will be a moose hunting round in an FN Mauser Supreme in 300 h&h. So , it will have to be reliable in late september/early october temperatures temperatures ( -10 at the coldest)
 
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From CCI website regarding magnum primers:

  • 23 percent hotter flame than standard primers
  • Increased flame duration
  • Initiator compound engineered to ignite
    ball/spherical propellants
  • Improved sensitivity for “critical-need” loading

USAGE:


  • Large capacity cases
  • Heavily-deterred propellants
  • Ambient firing temperatures below 20° F
  • Usage Note: Use Magnum primers only where
    called for in published reloading data
 
I've used standard CCI 200 primers with 7mm Rem Mag / IMR 7977 with good ignition, also RL22, RL23, IMR 4831
 
pacobillie said:
I know that they are similarly priced. Just looking to optimize velocity and accuracy. I read that for "reasonable magnums" you might actually get more speed and consistency out of standard (power) primers. Btw, this will be a moose hunting round in an FN Mauser Supreme in 300 h&h. So , it will have to be reliable in late september/early october temperatures temperatures ( -10 at the coldest)
Click to expand...

I'm shooting a 7mag and a 7 SAUM right now, just curious as to the reasoning since I think both of mine would be considered a medium sized cartridge.
I've never heard anything about a regular premium primer being more consistent than it's premium bigger brother.
Was there some testing somewhere that supported these claims? Or was it something someone heard at a gun counter somewhere?

If they're just for moose hunting in a mauser do you really think it matters? Or if you'd ever actually see a difference that couldn't be written off to things like not using a match bullet or some rifle factor like it may not be accurate enough to ever notice a difference on a paper target?

I think you may be overthinking your moose loads.

I would use whatever your favorite magnum primer is, find a suitable bullet and a temperature stable powder that shoots less than 2 moa in your rifle and just go fill your freezer every year.
When you have a rifle capable of 1/2 moa and you're hunting paper at 500 yards your question will be much more relevant.
 
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Even the American military Lake City 5.56 and 7.62 ammunition use magnum primers. Our military prefers to use double base ball powders that are harder to ignite than single base powders.

Double base powders contain nitroglycerine to increase its energy but also have more deterrent coatings to slow down the burn rate. And slow burning single base powders also have more deterrent coatings than their faster burning single base counterparts.

Basically a magnum primer burns a little hotter and longer than a standard primer, but this can vary between primer manufactures.

Below a Winchester large rifle primer.

GASWWLR.jpg
.

Below a Remington 9 1/2 large rifle primer.

GASRem95LR.jpg


Below a CCI BR4 Small Rifle primer.

GASCCIBR4SR.jpg



Below a Remington 7.5 Small Rifle primer.

GASRem75SR.jpg


Bottom line, when you are standing on your hind legs shooting at a running deer in cold weather I can't tell any difference in primers. But the largest caliber rifle I have is a 30-06 and for years all I used were Remington primers. Remington ran our Lake City Army ammunition plant from 1941 until 1982 and used 7 1/2 and 9 1/2 primers to light off Winchester ball powders. So go figure and pick the primer that works best for you.

Ultimate Large Rifle Primer Shoot-Out — 16 Types Tested
by Laurie Holland Target Shooter Magazine.
http://bulletin.accurateshooter.com/2017/04/ultimate-large-rifle-primer-shoot-out-16-types-tested/
 
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I never thought that primers could make a difference on group size until I tried it. My 300wm and 7LRM both shoot way tighter groups with Rem 9.5 large rifleprimers than they do with Fed 215m. I tried different primers in my 257wby and 270 wsm and it didn’t make any difference on group size between magnum and non magnum primers.
 
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