Used magnum primers in my .357 load by accident... result?

[DHart]

I was loading some .357 ammo last night. A load I use a lot: 16 gr. of 2400 with standard primers, powering a 140 gr. JHP. This gives 1200 fps from a 3" S&W model 65.

Normally a standard primer is specified for this load, but I inadvertantly used Federal Gold Match magnum primers instead of Gold Match standard primers. I believe this will result in higher pressure, but I don't think I'm quite at the limit on this load anyway. I went ahead and fired about 20 of them last night and they seemed perhaps a tad hotter than normal, but the cases looked fine and the primers looked normal after firing, so I didn't see any obvious signs of dangerous pressure. I didn't chronograph them.

Would you fire the rest of them (80 or so) or tear them all apart? Seems like I'm ok with this batch. Any idea how much the pressure is increased when going from a standard to a magnum primer?

 

[Bandit01]

I have a S&W 686, so far, I've shot a few thousand rounds threw it and I've always used Magnum primers. The 2 powders that I use for .357 are 2400 and H-110. And I believe that I'm using 158gr. bullets. Go for it, or ship them to me and I'll shoot them for you. lol

 

[stans]

You might be approaching maximum by using the magnum primers, but as long as there is no cratering and the fired cases are easily ejected you should be ok.

 

[Mark whiz]

You're fine.
As stated above, I too use mag Primers in ALL my .357 loads with no issues. I also use 16gr with 158gr bullets - it's on the higher end of the scale, but still below max for 158s and definitely below max on 140s.