new to 38/357, need little help with primers

S

Shadow9mm

New member
Just got a GP100 6in. Have loaded for 9mm, 45acp, 223, 308, 30-06.

What I am trying to figure out is primers. Currently all I have is small rifle and small rifle magnum. no pistol.

I have been using regular small rifle for my 9mm and figured they would be fine for 38spl

For 357, I'm still trying to figure out what loads or powders I would need magnum primers with. I am hoping I can use regular small rifle since the cups are thicker, but was concerned there would not be enough flash. An that there could be too much flash with a small rifle magnum.

For now the plan is to stick to 158g bullets for both 38 and 357. My current 2 powders are HP-38 and AA#7. What I find odd is the load data generally tends to jump over #7. It goes from #5 to #9.

I have a reasonable powder selection at my local shop. What are the good powders for a HOT 357 and a moderate 38spl(in the 1000fps range)

Any suggestions or advice is appreciated.
 
Mag primers aren't necessary with AA#7, and your standard small rifle primers will work just fine. And of course standard primers work just fine with HP-38 as well.

I believe some brands of small rifle primers are hotter than standard small pistol primers, although not as hot as mag primers. So you would want to follow the standard advice of going with a starting load and working up from there.
 
From what I understand you do not need magnum primers for 2400, but do for H110/W296. not sure on AA#9. Are other specific powders I would need magnum primers for?
 
If you use small rifle non-magnum, there’s really only one thing you need to know and one thing you need to do:

—need to know that your GP will pop every primer every time in double action. If you have used any non-original or non-standard main spring, you may have occasional FTFire with small rifle primers

—as far as load “safety” goes, if the primer fits the brass and the handgun will detonate that primer EVERY time, then you have no safety concern with a rifle AS LONG AS you develop the load using the proper method of load development. In other words, don’t ever take a handload that was balls-to-the-wall and right on the cusp of nuclear with a regular primer and simply start making the same load with a rifle primer, that’s how you go over pressure.

The opposite isn’t true. Don’t ever use small pistol primers in a round spec’d for small rifle, that’s definitely asking for trouble.
 
I was about to say that small pistol MAG would compare to a small rifle primer...
but stand corrected:
30513219gm.jpg


If you can get Vihtavuori powders, get N-110 for the 357 loads and use small rifle.
For 38 Special uis small rifle again and W231/HP38 and/or Bullseye
 
No loads at all yet. Will be working up from start. Won't be going over published max, but I will probably be going up to it with 357. The 38s will be kept at or under 1000fps.

It's all factory at the moment. But I do have a spring kit on the way. Will have to see how she does.

I'm still not sure what to do if I need magnum primers though. I'm hesitant to use small rifle magnum in place of small pistol magnum.
 
mehavey said:
I was about to say that small pistol MAG would compare to a small rifle primer...
but stand corrected:
30513219gm.jpg


If you can get Vihtavuori powders, get N-110 for the 357 loads and use small rifle.
For 38 Special uis small rifle again and W231/HP38 and/or Bullseye
Click to expand...
Interesting. So it would seem srm is weaker than spm but might work for some of the less sensitive powders
 
Consider Power Pistol for 38 Special. I use mostly AA#9 for 357 Mag, but H110 and 300-MP do well. Don't forget a good crimp, particularly on magnum loads.
 
They will all be getting a HEAVY crimp. I love power pistol, but I can't get any right now. It's been 6 months since I have seen any.
 
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Concerning primers, I have a stock of Winchester LPP. They make no distinction between standard or magnum charges, but are good either way.

Dunno bout Winchester small pistol primers, if they say the same. It's interesting that neither my CCI large or small pistol primers make that distinction. Nor do my Remington or Federal pistol primers.

Interesting. I wonder why that's the case.

{Edit: Please see board rules on posting copyrighted materials and on hotlinking to images hosted on other sights.}
 
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I believe your asking for a problem at some point. There's probably a good reason why they designate the difference between rifle and handgun primer's. I'm not an engineer so I simply take their word for it and don't exchange primers! I have no idea what the down side might be and no intention of finding out!
 
(Small) Rifle primers have harder cup/more brisance than pistol.
No big deal as long as:

- Load is worked up using the rifle primer (and usually not much 'effective' difference even then)
- The [revolver/pistol] hammer is strong enough to deal with the harder cup ('most' all the time it's OK)


Where you get in trouble is:
- Substituting pistol primer for rifle in high-pressure loads (possible pierced primers above 35-40,000 psi)
- Substituting Large Rifle for large pistol (Large rifle is taller primer -- stands proud)
 
Not sure if this requires a magnum primer, but using regular primers with IMR4227 I get unturned powder kernels in the bores of both my .357 and.41. Accuracy was excellent so I never messed with it. I don’t use it much anyway since I prefer 2400 which doesn’t require a magnum primer.
 
Like jetinteriorguy, I also use magnum primers with 4227. Won't say it's necessary, but just seems to leave a few less unburned kernels in the barrel.

Don
 
In my experiences small rifle magnum primers have noticeably harder cups and can be pretty hard to ignite. I wouldn't have too much concern with using small rifle primers in a GP100 assuming the gun can set them off.
 
Will have to test it and find out. I do have a spring kit for the GP 100 coming. Will have to see how it work before and after I change it out. I'm also curious to see if it has enough power to ignite something like H110. Based on the chart from mehavey its about 2/3 of the way up between small pistol and small magnum pistol.
 
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