OK to use magnum primers in 38 Spl cases?

I’ve interchanged them for a long time with zero issues (but YOU decide what’s best for YOU). Here’s a good video on the subject.

The Sierra manual recommends you drop your charge. Normally when I have had to use a magnum primer instead of the recommended one I use a slower burning powder. I have yet to have any issues or over pressure signs.

You will probably not notice and difference.
Lafitte

Smaug said:

I think I'll do this. Do you think it'll be enough to start with the min. 3.8 gr. load of Win 231 recommended by Hodgdon, or should I go lower? It's a revolver load, so no need to worry about not having enough energy to cycle the action.

Click to expand...

If your a grain below max I consider it a non issue.

Loaded 1k worth of 9mm with Remington 6.5 small rifle primers, not one bit of difference.

Smaug said:

I'm out of small pistol primers; only have small magnums. I want to roll up some 38 Spl for my LCR that's incoming. It's rated for +P. I'll use 125 gr. lead bullets and Win 231 powder, probably starting with 3.8 gr.

I figure the 38 Spl case is long enough that a magnum primer should be OK, especially in a +P rated gun, but I wanted to bounce it off of you guys.

Click to expand...

If you were using Nitro 100, Competition or TiteWad, something very fine grained and near the top of the burn rate scale, I would think about being a little cautious but that’s about all I would recommend. With W231 I doubt you’ll see or feel any difference. Switching a slower ball powder to a standard primer carries more risk.

As the guys said, drop your load a bit (recommended 10% unless you are already at minimum then a bit less). This is a good safety habit whenever you change a component. You can work back up as the load pressure signs allow.

I had to start loading all of my .32 H&R loads with small rifle primers, my Bisley firing pin is a bit long and it will pierce thin primer cups.

Stay safe.

I found no significant difference in loads when I subbed SPM or SRP for standard small primers. To be safe restart at starting load and work up in a couple or three steps just to be on the safe side.

Smaug said:

I figure the 38 Spl case is long enough that a magnum primer should be OK, especially in a +P rated gun, but I wanted to bounce it off of you guys.

Click to expand...

Yes, you can use small pistol magnum primers in .38 Special loads. In fact, the old Speer No. 10 manual indicated the use of their CCI No. 550 magnum primers with ALL their .38 Special loads with W-630, HS-6, HS-5, 2400 and Blue Dot loads (relatively slow burning or ball powder loads). If you want to reduce your charges from a previously worked up maximum load, fine. But I don’t think you need to go back to the starting load and work carefully back up to a “maximum with magnum primer” load. Chances are, you will wind up at, or very near where you were with the standard primers. Many have experimented with both small pistol primer types, and very few have noted major differences in velocity or pressures.

I've done it many times with no ill effects. You may chronograph about 25 - 50 fps faster but that's it.
When in doubt check your primers and make sure they aren't flattening out more than normal.

I bought a 1K pack of the small pistol magnums a few weeks ago. Having no experience with them I loaded up 14 rounds, half regular and half magnums,147gr blue bullets and True Blue powder. My results were kind of surprising to me, the magnums were a little slower.

What about using regular small pistol primers in 357 magnum loads?

Atomross13 said:

What about using regular small pistol primers in 357 magnum loads?

Click to expand...

I’ve loaded lots of .357 mag with standard small pistol primers with zero issues. I have found no difference between standard and magnum primers in any pistol load. I’ve even used small rifle primers in pistol loads and they run just fine.

Smaug said:

I think I'll do this. Do you think it'll be enough to start with the min. 3.8 gr. load of Win 231 recommended by Hodgdon, or should I go lower? It's a revolver load, so no need to worry about not having enough energy to cycle the action.

Click to expand...

Do not go below the recommended starting charge. All you need to do is work up a new load just like you would when you change any component. Hodgdon recommends 3.8gr to 4.8gr W231, if it were me I wouldn't even go as low as 3.8gr but since you sound like a new reloader start low and work up until you find an accurate load.

Smaug said:

The concern with that seems to be there ability to ignite the slower burning magnum powders. Maybe a higher chance of a hang fire...?

Click to expand...

No, you won't get a hang fire with a standard SPP in the .357 Magnum with the starting charge. The only powder that should be loaded with a Magnum primer are slow hard to ignite ball powders like W296/H110 and HS-6 and the like. Standard primers will still work but with a magnum primer you will get a more complete burn and lower SD numbers.

Being safe is paramount when reloading but over worrying isn't necessary. Try not to download those slow ball powders too much because they react much better at the upper end of their load range. (if you have a choice)

Smaug said:

I think I'll do this. Do you think it'll be enough to start with the min. 3.8 gr. load of Win 231 recommended by Hodgdon, or should I go lower? It's a revolver load, so no need to worry about not having enough energy to cycle the action.

Click to expand...

I think you will be fine. I think it will cycle the action as this powder is a medium burn rate even though you are loading the minimum.

Do let us know how it worked out, would really appreciate a range report.

i have a primer ft lb energy chart from cci, i will try to down load it has good info on it