Myth or fact? standard primer =1gr and magnum=2gr

[galvweld]

Learned at my Father's reloading bench, the strength of a man is measured by his language, his fists, and his firearms. He worked in an engineering lab as a tech under direction of college trained engineer. One vivid memory was his statement of fact. His statements required , "yes sir." He's been gone nine years so pretty sure I'm safe to ask if his rule was anything near accurate? He said a standard primer was equivalent to 1 grain of powder and magnum equal to 2 grains. Been shooting and reloading for a life time and read some research that discussed cup difference, seating depths, brands against brands, and some research from self acclaimed philosophers, experts, and guys at gun ranges. To further my dad's rule usage a reloaded would reduce the amount of powder when reloading. His trophy's included Dali sheep, Alaska moose, trophy mule deer from Colorado, Wyoming, javelin, and antelope as examples.

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[Wayne]

Maybe .1 or .2 but 1 , 2

 

[Certaindeaf]

A standard primer is equal to one standard primer and a ... you know the rest.

 

[galvweld]

Maybe .1 or .2 but 1 , 2

Good answer. I'm old enough to say those life lessons predated most published reloading manuals. Just reminiscent of so much gun talk then and now based on hearsay (internet today) around the shooting ranges.

 

[Steve M]

That would depend on the powder and primer as a minimum. What about those Winchester large pistol primers labeled for use in standard AND magnum loads?

The correct answer is of course "Yes, sir!".

 

[ma96782]

The various manufacturers of primers "play their own games" when it comes to why they have their primers marked Standard or Magnum.

That being said, I go by the rules of......

1) Use only data from a reputable source.
2) Reduce your loads when starting to make a new load or changing components.
3) Work your way up.
4) Watch for signs of overpressure.

Aloha, Mark

 

[JRuby]

It is very possible he knew a lot more than I but I have never heard that before
I have been reloading since 1982.

 

[Member 5605]

Myth.

Makes zero difference in my .308

I reloaded a bunch with magnum primers and 41.5gr of powder.

Ran out of magnum so said what the hell, used standards and nothing changed.

 

[RVTECH]

Ran out of magnum so said what the hell, used standards and nothing changed.

And vice versa - a couple years ago during the BIG crunch I needed some LP primers for .45 and all I could find were LPM - same load no reduction (I was below max anyway) and no difference. Matter of fact I once read if one shoots in a predominately cold climate he should load with MAG primers for all loads to ensure cold weather ignition.

 

[DizzyJ]

Oddly enough, pressures/speeds can sometimes be lower when using a magnum primer. Too many variables to have a fast and hard rule like that.

 

[etrain16]

Here is an interesting article on primers by Chuck Hawks: Primers, the Sparkplug of Centerfire Cartridges

Here are some excerpts:

The priming compound itself is an explosive intended to be detonated by percussion. (It can also be detonated by heat or flame.) There is typically less than one grain of priming compound in even the hottest primers. Never the less, primers must be handled and stored carefully. They are, after all, designed to start a fire. Store primers in the proverbial cool, dry place away from other flammables. High humidity degrades primers more than high temperature. According to CCI/Speer, properly stored primers will remain viable for decades.

Magnum primers are "hotter" than standard primers. CCI/Speer typically recommends that magnum primers be used with ball (or spherical) powders, when loading magnum or other large capacity cases, and when it is anticipated that the cartridges will be used at temperatures below 20 degrees F. Ball powders are generally harder to ignite than flake and extruded powders and magnum primers are often called for, even in non-magnum rifle and pistol cartridges. Let your reloading manual be your guide to primer selection.

Primers affect the pressure generated by the cartridge. Changing from standard to magnum primers may substantially raise the maximum average pressure of the cartridge and indiscriminate changes are not recommended. The A-Square Company conducted pressure tests involving six different primers. These tests used the 7mm Remington Magnum cartridge with a 160 grain Sierra BT bullet and 66.0 grains of H4831 powder and the results were reported in the A-Square reloading manual Any Shot You Want. A-Square used CCI 200 and 250, Federal 215, Remington 9 1/2M, and Winchester WLRM and WLR primers in these tests. They revealed a total spread in pressure of 12,800 psi from the mildest standard (the CCI 200) to the hottest magnum (WLRM) primer tested.

Changing brands but using the same type of primer will also usually result in pressure changes, but ordinarily these will be less drastic. In the A-Square tests the pressure spread between the CCI 200 and the hottest standard primer (the WLR) was 9600 psi. The spread between the mildest magnum primer (the Rem. 9 1/2M) and the hottest magnum primer (WLRM) was 8300 psi. These are significant pressure variations that cannot safely be disregarded.

Check out the link to the article for more details.

 

[Jamie6.5]

Matter of fact I once read if one shoots in a predominately cold climate he should load with MAG primers for all loads to ensure cold weather ignition.

This used to be true, and may still be with some powders.
In the day's of Hodgdon's paper bags of 4831 we had cold weather (<20*F) elk loads for our .270s.
They were compressed loads that called for magnum primers only.
Our fall/summer loads for deer were slightly lighter and used a std LR primer for the same bullet weight. (150gr)
Both chronoed at the same speed when used at the temps they were intended for.
IIRC that cold weather load came out of an old Lyman book.
It's a kickazz load for winter, but shows pressure signs at warmer temps.

Ball powders tend to yield more consistent velocities when used with mag primers as well, but there's usually a note about using them in the reloading data.

 

[v0lcom13sn0w]

as long as you dont put primers in with the powder to get that extra .1 or .2 youre gonna be ok.

 

[galvweld]

It is very possible he knew a lot more than I but I have never heard that before
I have been reloading since 1982.

He was teaching me to fight, cuss, and shoot and reload in the 1950's. Were he here he'd tell you! He raised me to be able to say, "I am not always right, but rarely in doubt." Thanks to all who have commented. Still learning to reload, learned cussing usually got someone's nose broken so fighting would enter the realm of self-defense. Shooting and reloading are like being followers of Jesus. As a disciple there is more to learn even at this stage of life.

 

[DirectDrive]

He said a standard primer was equivalent to 1 grain of powder and magnum equal to 2 grains.

Unactionable intelligence (useless information to be frank)
As stated above, use published load data and don't experiment.