[olp73]

If anyone have a clue of what is going on please let me know. I am getting cratered and/or flattened out primer strikes. The primers itself show no sign of flattening. Almost like this, but not that bad.
 Primer_flat_strike.jpg (71.16K)
Number of downloads: 192 (Picture is for illustration purposes only, it is not my case)
The strikes are on the light side (on primes without the symptoms.)
The gun is a new to me, hi-cap SVI 5” Schuemann ultimach barreled IPSC standard gun. I bought it lightly used and this is the first time I am loading for this gun.

My starting load is/was:
5.0gr vv n320 behind a Frontier 180gr bullet. Fiocchi sp primers(on the hard side) and cases. OAL 1,18”. I am familiar with all of these components. Used them a lot before and never had problems.
I found an article in a reloading manual (Norwegian one) addressing the issue. It states that it doesn’t have to be a high pressure problem, but can be among others things:

-too pointy firing pin
-firing pin is not sitting tight enough in the firing pin hole (lose fit)

I have also measured the “pressure ring” above the case head for expansion. And there is absolutely no bulge in the cases what so ever.
As many of you will know this is not suppose to be a hot load. Most likely it doesn’t even make major, but should be close.
I am thinking of buying one of those XL firing pins, but does that really solve the problem or just camouflage it? Maybe I have a pressure problem?

This post has been edited by olp73: 07 November 2009 - 10:26 AM

[Hi-Power Jack]

olp73, on Nov 6 2009, 05:46 AM, said:

The strikes are on the light side (on primes without the symptoms.)
Maybe I have a pressure problem?

Primer does not look too flat to me.

I just sent my gun off to the gunsmith because of what looked like
light hits on the primer - he said it's because the chamber was
extremely tight, raised pressures and caused the primer to flow
back - looked like a light hit, but wasn't - just the primer flowing
back into the indentation.

[ebg3]

Put an XL firing pin in the gun and never look back! The long pin will cure any primer flow problems and will allow you to use rifle primers, if you want to, with a light mainspring and you won't have any light strikes.

[Guy Neill]

The fit of the firing pin in relation to the firing pin tunnel can also play a part of the firing pin diameter is too small compared to the tunnel diameter. Too much room may allow the primer to flow into the tunnel, as the photo shows.

Guy

[CocoBolo]

Ok, lets hope that you are not using 5.0gr N320 with a 180gr bullet in a 38 Super going by the picture.. If you are you need a much slower powder and accidental life insurance. N320 plays out at 130gr bullets.

My guess is that you are loading 40 S&W and that said 4.8- 5.0gr with 180gr jacketed bullet is about right for a 168-170pf. The OAL could be out to 1.20 with an SVI. With a moly coated 185gr bullet you can get there with only 4.4gr N320. I use federal small pistol with these loads and they are the softest primers you can find.

The offset punch is common and the police can match it to the gun that shot it becuase they all vary slightly. The main thing is it goes bang and does not poke a hole in the primer, that pic is a shallow dent.

[calishootr]

yrs ago we tried everything to prevent primer flow, even turned down a .45 auto pin to fit the .38 super, no dice, still flowed, tried a XL pin and never looked back, the xl pin will actually protrude thru the breechface when the hammer is down, preventing in this case any flow from gettin in the tunnel and screwin things up....