magnum primers

[j0nthegreat]

so ... i accidentally bought 1000 magnum small pistol primers instead of regular (cci) ... i've read you should use standard unless specifically instructed to use magnum, but is it really that big of a deal?

i've skimmed through my manual and npthing really seems to call for magnum small pistol primers ..


i'd be using them for loading .38 special (and +P, +P+) and .357 magnum .. with 158gr bullets.

 

[BradMacc82]

I'd THINK you'd be ok, but I don't load for .38 - so...

 

[guthook]

Just breezing through Speer #14 I saw several .357mag loads using Magnum Small Pistol primers.

 

[tech24]

They'll work fine.....may want to work loads up from start though as they can be hotter loads with less powder but not always.

You certainly wont blow your face off if you start off easy on the powder

 

[j0nthegreat]

i didn't think i would.. .38s are pretty pathetic anyway.. a hotter primer couldn't make it into a .357.

i may wait for one or 2 more replies to ease my mind but i expect to use these up quickly. thanks folks!

 

[tech24]

I'd like to hear some more replies as well. I try magnums for rifles at times and sometimies find more velocity, consistency, and accuracy. But thats with rifles and slow burning powder so its not the same.

I'll edit my post and to say it should be fine and the slower burning powder you are using the safer they will be....in theory. Personally with my current loads I wouldn't even change powder weight as they aren't near max. I have 3k win small pistol primers left if you wanna trade out some I could do that as I'd be curious to do some experimenting with 9mm loads.

And magnum primers aren't neccesarily (spelling) hotter they are just designed to ignite slower harder to ignite powders.

 

[j0nthegreat]

i'd be happy to do some trading if you want

 

[ALBY]

i load .40 pistol with small rifle primers all the time.

as long as you are not on the ragged edge, velocity wise, you should be fine.

drop your charge a wee bit and test a few over the chronograph.

I think the main difference between SP and MSP is the cup thickness. magum loads can flow around a SP primer and score the breechface, hence the thicker cup.

 

[alucard0822]

Magnums do burn hotter/longer than a standard primer of the same brand, however there is some difference amongst brands too, so whenever you change ANY component, work up the load again, I know of some Win primers that list for "standard or magnum", and some "standard" primers that give velocities and seem just as hot as another brands "magnum". Even something you think won't matter like the brass may be thicker or thinner, and have more or less internal volume leading to changes in pressure. A hotter primer can be beneficial with low temps, big cases, and slow ball powders, giving more consistent ignition.

In the case of substituting magnum primers for a load calling for standard, it stands to reason fast easy lighting flake powders like bullseye would give more pressure and higher velocities, but I haven't seen much of a change. Years ago on the high road forum one senior member called the tech assist numbers of a few powder and primer companies asking this question and posted responses, all told him Magnums COULD be substituted for standard, working up the load with a suggestion of the standard starting load, -20% of the max, or -5% of standard starting load depending on company, point is the powder/primer companies said it could be done and was safe. Standard primers should NOT be substituted for magnums due to the danger of squibs from partial ignition.

I have a lot of loads that I use magnums for when not required, being they were worked up during the primer shortage a couple years ago. I used Magnums when standard primers weren't available, and still have magnums and load with them. There is no real reason for me to switch back, or work up another load with standard primers till all the magnums are gone, and even then there isn't a need to. Some of these loads, like .223 with H335 or BL-C2 actually shot better with a mild increase in velocity but better consistency. Service caliber handgun loads with HS-6 or Win 231 were about the same in 9/38/357/40/45, other powders like bullseye, unique and Power pistol had a mild increase in velocity. I've never had issues with these loads, even though some are at or above published loads for standard primers, and all were worked up carefully.

 

[DocAitch]

In the recent primer/powder/toilet paper shortage the only primers that I could obtain were 5000 CCI SP Magnums and I used those in 9mm and .38 special regular loads. I started low and stopped at either a decent level of accuracy for the .38 and or when my pistol cycled reliably for the 9mm.
I am sure it is safe to do so, I don't know if the accuracy suffered because I shoot offhand at 25' (never tried for groups from a rest).
I would be hesitant to use magnum primers in .40 S&W because of the pressures involved (and because I had a KABOOM with a .40, so I'm a little shy).
DocAitch

 

[Cowboy T]

+1 to the others. Just drop your charge some and work back up. You should be fine.

 

[j0nthegreat]

great, thanks everyone!