Small Pistol Mag Primers

[Stumps13]

With the supply of primers being what they are, please answer this question.

Can a small pistol mag primer be used in a 38 special load? The load would be 4.5 gr of Universal pushing a 158gr lswc. :roll:

Thanks

 

[Cholo]

Yes. My Lyman book shows a max. of 4.7 grs. with a CCI 500 primer which is their standard small pistol primer. I'd back off to 4 grs and work up.

 

[Iron Mike Golf]

Back off 4.0 gr or 0.4 gr?

 

[Cholo]

"I'd back off to 4 grs..."

 

[Cheesewhiz]

My concern would be 'gascutting' with a magnum primer and a standard (lighter) load. Magnum primers are made to withstand magnum pressures, they don't seal well at lower pressures.

 

[Iron Mike Golf]

Gotcha, Cholo. Missed that "to"

 

[Jimbo357mag]

My concern would be 'gascutting' with a magnum primer and a standard (lighter) load. Magnum primers are made to withstand magnum pressures, they don't seal well at lower pressures.

I thought I read somewhere that a magnum primer has a little more compound in it, that's it.

Rifle primers are made to withstand higher pressures. :?

 

[Cheesewhiz]

I thought I read somewhere that a magnum primer has a little more compound in it, that's it.

Rifle primers are made to withstand higher pressures. :?

It may just depend on the make but it is something to look out for.
I remember during the last great primer shortage, an avid shooter using small magnum pistol primers in his reloads for minor PF.
His Glock ended up with some gascutting to the breach face and the slide was pretty messed up by this. I use small mag primers only on major loads and I watch for any leakage on any reduced loads.
A harder or thicker walled primer is more likely to do this over a softer one and it seems to be of greater issue with small primers, which makes sense if you think about it.
It is easy to check if you are getting any leakage with a load, you'll see the blow by around the primer.

 

[Rick Courtright]

Hi,

Wondering out loud if the "leakage" is a function of the TYPE of primer, or more a mismatch between a brand of primer that's ever so much smaller than most, and a case w/ primer pockets ever so much larger than most? In any case, there are primer sealants out there--mainly for weatherproofing--that might help seal things up in such a case. Just don't be in a hurry to get some really high production numbers while using them.

Rick C

 

[m657]

The last primer-shortage episode I was caught low on SPP for my ICORE 38 loads....had to load a moderate level 130 RNFP with what I had on hand.

After a year's worth of matches burning those up, I was unable to detect any issue involving erosion or cutting. And for what it's worth, there was no noticeable difference in performance for accuracy or comfort in shooting them. In fact, other than the different packaging, I wouldn't have noticed any difference at all.

 

[mattsbox99]

I know lots of people that only use small pistol mag primers, many are competition shooters. Some even use small rifle primers with no problems.

The group of guys I shoot with every week all use SPM primers in all their loads including .38 SPL.

 

[Cheesewhiz]

My point is a cautionary one, during any type of component shortage, changing over to a different make or rated product can have an effect on your pet loads.
I have seen this before and especially during the period four years ago.
Primers are kind of a voodoo thing, there are some that only use something that has CCI on the label. Lyman books tend to attribute magic powers to primers, other books wave a wand to a lesser degree.
I've had primers explained to me at least a hundred times and read even more on them, almost always there was no true consensus.
I do know that primers are different, not just in their ratings but in their make up and make. I use soft primers for loads in my modified hammer fired guns, Federals and Remington, Wins when those aren't available.

...and I know if you google "gascutting primers" you will get about 300,000 hits, mostly from the Brian Enos, THR and AR15 forums and very many of those links have to do with a mag or rifle primer used in a light (standard) pistol load.

I can tell you that I have seen a G17L with a very messed up slide and that slide was destroyed by gascutting and that guy has been reloading for a fair amount of time, it caught him by surprise for sure and I don't like surprises, that's why I check things after I make a change from a norm or I am working on something new.

 

[Stumps13]

Thanks for the info. I was lucky enough to find a brick of small pistol primers yesterday so the problem has been solved.