MAGNUM primers question.

The number one difference in general between a magnum rifle primer and a regular rifle primer is cup thickness. The magnum being thicker. As far as how hot they are, it differs from one manufacturer to the next.
Brand “A” large rifle primer could very well be “hotter” than brand “B” large rifle magnum primer.
That being said, I’ve heard the Winchester primers burn hot. I don’t use them anymore because they are very slightly smaller diameter in LR and don’t seem to seal as well when loads get up there.

All LR primers, magnum or not have a cup thickness of .027". There may be exceptions but I am not aware of any. If I can develop a load with a mag primer I do. It has never done anything but benefit me as far as rifle goes.

I have nearly blown up a pistol trying to redevelop a load using a magnum primer though. That data was scrubbed from loading manuals a long time ago though so there may have been other factors at play.
 
Years ago I had a few hang fires in 30-06 using ball powder and light bullets, no crimp with lr primers. Bad combination. Now I use mag primers for all ball powder loads except in small cases like 223.
 
Does all loads using ball powders need magnum primers?
I used H380 in my 22-250 and 220 swift with the WLR primers and had great performance.
The load I'm starting now is using a powder with a burn rate similar to H4831 and H450.
It is 47SB (ball powder offered by higginsons years ago) I've been loading in 303B. With a cast 185gr .

Ahh, good old 47SB. That's the powder I've loaded my ugly old sporter 98 in 8mm/06 with for a good many years. I use it solely in my "hunting loads" topped with some old Sierra 150 gr. spire points. I've only ever used std primers, probably either Winchester or Federal. 47SB is a real ball powder, something I don't use much of.
 
All LR primers, magnum or not have a cup thickness of .027". There may be exceptions but I am not aware of any. If I can develop a load with a mag primer I do. It has never done anything but benefit me as far as rifle goes.

I have nearly blown up a pistol trying to redevelop a load using a magnum primer though. That data was scrubbed from loading manuals a long time ago though so there may have been other factors at play.
Not the dimensions of the formed cup, the thickness of the material it’s made of. Magnum primers use thicker stock to withstand more pressure.
 
I suppose if your going for .1's in bench rest, I would use bench rest primers.....at least thats were I would start. If I'm three days from nowhere, two weeks of.holidays, $1000 in fuel......im using a magnum primer, probably a magnum that burns three 223 cases of powder as well. It absolutely has to work, when I have a freezer full of meat in front of me.....its not bench rest.
 
Not the dimensions of the formed cup, the thickness of the material it’s made of. Magnum primers use thicker stock to withstand more pressure.

That doesn't even make sense. Some stock will be harder or softer, sure. Thickness is .027" regardless of brand though. It's easily confirmed with a simple internet search. Large rifle primers do not have different thicknesses unlike SP, LP and SR primers.

 
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That doesn't even make sense. Some stock will be harder or softer, sure. Thickness is .027" regardless of brand though. It's easily confirmed with a simple internet search.

What part doesn’t make sense? I’m happy you can work the internet, but thicker material can take more pressure. It’s a metal thing...
Varying cup thickness is also all over the internet. I’m not sure where you read that all primers are .027” thick, because that’s not true. I’ve personally measured quite a few.
 
What part doesn’t make sense? I’m happy you can work the internet, but thicker material can take more pressure. It’s a metal thing...
Varying cup thickness is also all over the internet. I’m not sure where you read that all primers are .027” thick, because that’s not true. I’ve personally measured quite a few.

If something is a certain thickness then it is a certain thickness. This argument is nonsense. It doesn't matter what they are using because the end product is nominally .027".
 
You are right that the actual composition of the brass probably has more effect on the effective “hardness” of a primer. And the cups in my experience have only varied by .003”-.004”.
What I was mostly insinuating was that there wasn’t necessarily more of a charge when comparing magnum to non magnum primers. One brand of standard primer can be hotter than another brand of magnum. There’s no standard for how hot they are. This basically means you should go ahead and use whatever primer you want as long as the load is worked up.
For the most part, in my experience, magnum primers are harder. Whether it’s cup thickness or material hardness or a combination of both, I don’t know for sure. I’m not a metallurgist. I can only physically measure.
 
^The priming compound can certainly vary wildly. As mentioned "standard" Win primers are quite hot, likely more so than some Magnum offerings. I have some RWS large rifle primers not marked as magnum that will spit flame out the end of a 20" barrel, very hot and energetic.

Primer choice can make or break a load if you are picky. I use rifle primers in pistol loads in some instances to produce better SD and usually higher velocities. That extremely hot Rem 7.5 pictured is my favourite for .454 Casull as it brings the SD down to single digits, something no other primer I have tested can do.
 
Primers are not all the same. Hence my experience can be different than yours. I use a lot of ball powder, usually with a standard primer. Twice I have found loads with serious ignition problems that a magnum primer solved.

I took these pictures by shooting rifle primers in a 45 ACP revolver.
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If you think these "standard" primers are the same, and interchangeable, I have a Cooey Olympic Match Rifle to sell you.
 
Ganderite,
Quite often I watch GunBlue490 on youtube. He said that magnum primers are not needed, even for ball powders, unless you use more than 60 grains of powder. Do you agree with this statement?

I have read 80+ grains for magnum primer. But I only know enough to get me in trouble.
 
That all goes out the window when its cold outside, you're using ball powder, or you're loading brass with more than 50 grs of powder. Are your handloads for benchrest or hunting? I'd sooner use magnum primers in either the .22-250 or the Swift, or in my .223 for that matter, if I was calling coyotes during the winter. Because I am never sure when my ammo will be used, I use magnum primers in everything, and with the majority of my loads, I can count on 3 shot MOA groups.[/QUOTE

Worked in the Arctic for a few years with scientists doing wildlife sampling. They were using standard .223- .308 factory ammo. We are talking -30 c all day long, sitting in a magazine exposed to cold.

I do hunt coyote in winter and use .223 / H335 with standard primer. The fact that you use magnum primer does not mean your reload will not perform with standard primer. It’s in your thinking that magnum is needed in cold weather. Military ammo is not divided in winter and summer load. GI using the 30/06 in the Garand in Europe and in Korea used standard ball load - not modified ammo with magnum primer.

It is a urban myth that you need a magnum primer in load used in winter. I have yet to see a reloading manual or publication that have summer and winter load and, commercial ammo loaded offering with two different primer - one winter and the other summer.

If published data does not call for it, it’s not needed.

A few years ago I conducted a cold weather primer test with cartridges across the common sizes .222 magnum, .270, .30/30, .30/06, .375 Ultra, and .458 where the same loads were fired with both standard and magnum primers. I thought I had slam dunk proof to support my position that magnum primers provided more consistent results than standard primers in the cold, but rereading it now, it seems the results were inconclusive. The first problem I had was that the chronograph had problems seeing the shadow of the bullet passing by due to the low angle light and ice crystals in the air, so perhaps all of the readings were suspect. Anyway, as noted my opinion as to the benefits of using magnum primers at low temperatures is not shaken. In conditions where a propellant produces lower pressure, a sharper spark that raises pressure within the case cannot be a bad thing.

CCI claims their #41 and #34 military primers are magnum formulations.
 
Ball powders are harder to ignite, because of the coatings used.

Ignition is a function of temperature and pressure.

Pressure depends on how full is the case? and how heavy is the bullet? How firm is the crimp?

The worst situation is a light bullet over a light load, no crimp.

You originally used a Winchester primer. Winchester loads their ammo with Olin (ball) powders, so the standard Winchester primer is made hot enough to ignite ball powders.

A magnum primer burns longer and helps boost temperature and pressure. If you use magnum (or a Winchester) primer you are improving ignition - a good thing.

With many hunting loads (full case, heavy bullet) a regular primer will work just fine. The problem is that you can't tell how close you are to failure. One cold day, on a hunt, you might find out.

What would failure look like? Higher/Lower velocity? Increased/decreased pressure? Thanks...
 
What would failure look like? Higher/Lower velocity? Increased/decreased pressure? Thanks...

I have had failure in several formats.

1. Primer fires, pops the bullet into the throat but no bang. This is dangerous because you open the bolt and may just see an empty case and think you forgot to load. The next shot can be exciting...

2. Primer fires, no bang, bullet stays in case.

3. Click.... bang A hang-fire. I once loaded my 8mm Mauser brass with some 90 gr pistol bullets, with H335 and standard primers. Every round was a click... bang. Good for teaching follow-through.

4. Bang but poor groups and a large ES. Erratic ignition.
 
What would failure look like? Higher/Lower velocity? Increased/decreased pressure? Thanks...

I have had failure in several formats.

1. Primer fires, pops the bullet into the throat but no bang. This is dangerous because you open the bolt and may just see an empty case and think you forgot to load. The next shot can be exciting...

2. Primer fires, no bang, bullet stays in case.

3. Click.... bang A hang-fire. I once loaded my 8mm Mauser brass with some 90 gr pistol bullets, with H335 and standard primers. Every round was a click... bang. Good for teaching follow-through.

4. Bang but poor groups and a large ES. Erratic ignition.

You should look into the powder you use..if the primer goes bang..the problem is elsewhere.
It seem you have more problems with your reload that I got in 50 years of reloading, and I shoot close to 15K. every year - all seasons in outside range pistol - rifle. I do my hunting load. Have not purchased factory ammo -other than rimfire - since I started reloading..and I can count in one hand the time a round did not fire.
 
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40 years ago when I lived in Alberta I tried H 414 in 30-06. Shot great when I worked it up at 25 degrees. But when I tried it at -15 I got that click bang hangfire. It was something I knew about but it was far more disconcerting to actually experience. Magnum primers cured the problem.
 
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