Standard primers?

[nvshooter]

Have run myself out of Magnum primers. Desiring to ignite 62.0 grains of Accurate Arms 4064 powder. Will primers for Standard loads do it? If the timing belt on my vehicle had not broken on July 3 and had several valves not been bent in that event, I'd just go buy a 1000-count box. But it's a long walk to Reno and back to affect the purchase. I have an unopened box of Standard primers; would like to use them to get the last bunch of .358" mildcat rounds loaded. Thanks.

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[11Charlie]

That is a great question but I would venture to say no. If they did it would change the continuity of the round as magnums burn hotter and faster.

 

[nvshooter]

If they did it would change the continuity of the round as magnums burn hotter and faster.

Got this absolutely insane idea about loading-up one or two and firing them over a chronograph; might reveal the answer. Or an answer. Before I fired a second round, I'd look down the bore to see if any unburned kernels of powder were blown down the bore but not burned. I was once told by a gunsmith that if a bullet runs over too much unburned powder, it can bulge the bore... and that's the end of that barrel.

 

[11Charlie]

Got this absolutely insane idea about loading-up one or two and firing them over a chronograph; might reveal the answer. Or an answer. Before I fired a second round, I'd look down the bore to see if any unburned kernels of powder were blown down the bore but not burned. I was once told by a gunsmith that if a bullet runs over too much unburned powder, it can bulge the bore... and that's the end of that barrel.

OK now we are talking!! Wish to god I was there I love a good science experiment!!

 

[nvshooter]

OK; now we are talking!! Wish to God I was there. I love a good science experiment!!

You could perform such an experiment right at home. Load-up any shell with a .532" head with a published load, use a Standard primer and go fire it.

 

[nvshooter]

That is a great question, but I would venture to say No. If they did it would change the continuity of the round as magnums burn hotter and faster.

I looked around the web at several other firearms-related sites. I read "information" about ball versus extruded powders, case volumes, ambient temperatures, burning speeds of various powders, combustion pressures and a bunch of opinions from A to Z. I appear to be left with having to load-up five with Magnum primers and five with Standard primers, and to then calculate the statistics for each batch. I'm a big fan of a low Standard Deviation, meaning less than one percent of the median value. If we get a median of 2700 fps, I want the SD to be 27 fps or less. I get giddy when I get it down to one-half of one percent. Doesn't happen too often, but it's really a joy for me when it does.

 

[nvshooter]

Have run myself out of Magnum primers.

Found a 1000-count box from January of 2007-- the good ol' days before November 2008. Had completely forgotten I had it. I was using Winchester LRMs; those are the ones that ran out. Had a 100-count flat of Remington 9½M; ran those out, too. Was looking in my secret closet for something entirely different when by sheer happenstance, I looked into a closed box that has been in the closet for years and years. Found the box of Magnums, another of Standards and several boxes of Small Rifles. I'm flush! Loaded-up a bunch of .358-caliber mildcat rounds with 250-grain bullets and hope to get them chronographed one of these weekends when my buds can all find some time off to spend an afternoon slingin' lead...

 

[AMproducts]

Good find. To answer your question...

4064 isn't as slow as some, but it's pretty slow, and a non-magnum might not be up to the challenge. It's worth noting that each vendor has different things they consider magnum and non-magnum. I've had major differences going from standard CCI so magnum Federal, and from Standard Federal to Winchester. In general, I like using magnum primers as they will usually kick off a load with more authority than a standard primer. That being said, it can also cause the pressure to spike much faster, and then you get other problems so they're not always the ticket for a standard load with a decent amount of powder. In general what you will see when you're in a light load switching from a magnum to a standard: Lower velocities, more unburned powder. From a heavy load magnum to a standard load: erratic velocities, failure to ignite (extreme case). From a standard hot load to a magnum Higher peak pressures, blown primer pockets. This is due to the faster ignition of the faster burning rifle powder.

 

[v0lcom13sn0w]

what caliber? general rule of thumb is to reduce loads by 10% when going from STANDARD to MAGNUM primers. i would say if you have a good load using magnum primers, a standard primer isnt likely to damage your weapon but it will burn differently possibly losing velocity, consistency(standard deviation may increase), accuracy...or...you could be just fine. only one way to tell.

 

[nvshooter]

What caliber?

Either of my two mildcats. Each is exactly the same to the shoulder. The .300-caliber holds 74.3 grains of IMR-8208XBR to the bottom of its neck. I use that small-ball powder to measure case capacities because it's easier to handle than water. The .358-caliber is probably just a grain or two more. The heat is off, though. I found a 1000-count box of CCI 250s; won't have a problem for a bunch of years to come. I'm in excessively poor health, so it's a 99.44% chance I'll keel-over dead before I use-up the new box...