Magnum pistol primers

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kinser11

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Recently, I discovered I had inadvertently purchased a box of small pistol magnum primers.:banghead: Has anyone had experience using magnum primers with reduced loads or does anyone know of commercial documentation (website) which specifies reduced loads for a given caliber. As a last resort, I could return them, but the gun store is about 125 miles from here. Any suggestions or ideas would be appreciated. Thank you
 
Maybe.

Well, I've asked that question before, and been told that it's okay.

That's NOT data coming from the manufacturer. That's opinions voiced here and in other forums.

I bought some mag primers that were way cheaper than another brand of standard pistol primers (and mags were the only cheap ones). I loaded them in .38 special cases with light to moderate charges as "range plinking ammo," which was the intended use in the first place. I shoot a lot of .38 special ammo in my .357 mags, so if there were a chance to get a bit more boost out of that ammo, I figured I'd still be safe:scrutiny: .

I shot up the 2,000 rounds of that some time ago..... no surprises, no signs of overpressure, nada.

I don't make any guarantees it's a good idea or a safe practice. I made my decision and that's what I did, those are the results.
 
You can subsitute magnum primers for standard primers as long as you are willing to start 10% below a maximum powder charge (not to go below minimum powder charge) and work up watching for over pressure signs...
 
what cartridge are you reloading for? I just had this problem with .357 magnum and alliant 2400. I wanted to make top end loads for my ruger vaquero. After a week of checking things online and reading some manuals i found that with A2400 and a few other powders, magnum primers were fine to use; but the load had to be reduced...by MUCH MORE than 10% of maximum. I can't remember for sure but the manuals that used magnum primers for .357 were the new speer and nosler books....could be wrong about that.
Just to give you an idea of the powder difference between magnum and non magnum primers with that powder combo... one book listed a maximum charge of 2400 w/ a standard primer at 15.2. Another book listed the maximum charge of 2400 w/ a magnum primer to be 12.3 So if you have accesss to them check out a few different reloading manuals. Otherwise keep the mag primers and buy a box of regular primers as well. That to me would be cheaper than running 250 miles round trip.
 
When I was experimenting with primer substitutions many years ago, I was told by a CCI enigneer that if you have a pet load that is below max with standard primer, you can reduce that load by 5% and work up in very small increments.

If you do not have an estabished load, start at minimum and work up. As my personal standard, I did not load over 3% less than the max, because there are no reliable pressure signs in pistols.
 
You will need to shoot them because I doubt very many stores would take them back or exchange them.
Powder & primers are generally not returnable due to liability issues.

Anyway, as already noted, unless you are pushing the envelop with a hot load, you can use them interchangeably with standard primers.

They will increase pressure somewhat, but if you are only at mid-range or starting load pressure already, there is nothing to worry about.

rcmodel
 
I am reloading for 9mm using a Sig P229. I will be using a 115 gr Nosler HP with Titegroup powder @ 4.6gr. I noticed that there seems to be a great variation in the amount of powder recommended for the same weight and style of bullet for different manufacturers.
 
Yes there is.

Every manufacture uses different pressure test equipment, test barrels or guns, and other variables.

One companies lawyers may even be more cautious then others.

Bottom line is load data is just a guide that will for the most part, always keep you in safe territory.

That's why you need to look at more then one source of data and kind of read between the lines.
Then start at the starting load and work up.

rcmodel
 
Thanks rcmodel. Another thing that disturbs me is when I purchase a particular bullet from a manufacturer and than find out they don't even list it in their own reloading manual. Than you have to consult 3 or 4 other manuals for basically the same type of bullet only to find out there is differences in OLL , ballistic coefficient, and the powder you want to use isn't even listed. I'm sure you have experienced this same scenario. It certainly makes reloading challenging and rewarding when everything comes together. If not, watch for my obituary.:D
 
what cartridge are you reloading for? I just had this problem with .357 magnum and alliant 2400. I wanted to make top end loads for my ruger vaquero. After a week of checking things online and reading some manuals i found that with A2400 and a few other powders, magnum primers were fine to use; but the load had to be reduced...by MUCH MORE than 10% of maximum. I can't remember for sure but the manuals that used magnum primers for .357 were the new speer and nosler books....could be wrong about that.
Just to give you an idea of the powder difference between magnum and non magnum primers with that powder combo... one book listed a maximum charge of 2400 w/ a standard primer at 15.2. Another book listed the maximum charge of 2400 w/ a magnum primer to be 12.3 So if you have accesss to them check out a few different reloading manuals. Otherwise keep the mag primers and buy a box of regular primers as well. That to me would be cheaper than running 250 miles round trip.
Hoopie,
I don't know why you found such a big difference between standard and Magnum primers but I have never found that to be true. They are a little hotter but not where you would need a 20% drop in powder charge like you mentioned. I've found you usually need to drop the charge 2 to 3 tenths, not 2 to 3 grains.

kinser11,
Just use a little care and you will be fine. Magnum primers are a little hotter but not a huge difference. As a matter of fact, Winchester Large Pistol primers are rated for both standard and Magnum applications. They couldn't do that if the 2 primer were that different... Magnum primers are usually only needed for powders that are hard to ignite like H110/W296. They insure proper ignition and more complete burning of the powder.
 
The magnum primer load i mentioned was in the Nosler Reloading Book NO. 6, and the non-magnum primer load was listed in the Lee "Modern Reloading Second Edition" reloading manual. Sorry, don't have page numbers. Those were MAXIMUM LOADS w/ a 19% difference.
So if you do the math... 10% off the Lee NON-mag load, is still almost 10% MORE than the maximum Nosler mag load. I've never before seen anyone tell someone to start 10% MORE than a manuals recomended maximum and work up. I might not have a whole lot of experience reloading, but i wouldn't trust anything but what was published.
 
Wow, you lost me now. Just because one manual lists a Max of "X" and the other lists a Max of "Y" doesn't mean the difference is due to the primer used. Their testing methods and their lawyers are different so they list different charges. Check 5 manuals and you will get 5 different Min/Max charges even with the same primers.
 
The points are,

1. Out of the 8 or 9 manuals I looked through, the Nosler manual was the
only one that listed a magnum primer for the specific powder and bullet
weight that i wanted to use. And that Nosler load was significantly lower
than any other book w/ the same bullet weight with a standard primer.

2. If someone would have told me what this guy's been told... to wing it
with joe shmoe's philosophy and you'll be fine, any of the suggestions
mentioned would have given me a charge that was well over the only
maximum load published for a magnum primer.

3. Maybe you've gotten lucky for however long you've been reloading.
I wouldn't start with anything but what i saw published to be safe.
 
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Hoopie: I do not have the current edition of Nosler's, mine being #4. It has no references at all regarding the use of magnum primers. Guess I'll have to buy a new book.
 
If you can look at a bunch of manuals without buying one i'd do that. There might not be any recommendations for your powder w/ a magnum primer...then again there may be a ton of them.
 
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