Pierced primers...

[DNA]

While tossing some brass into the bucket tonight, I noticed that 7 of 50 primers were pierced. From the reading that I've done, I know pierced primers are bad, caused by over pressure and possibly sharpened edges on a hammer and other not so fun things. These are brand new ammo from Miwalls, the 158grn FMJ .357 Magnum rounds, and are being fired from a S&W M27-2 with the 8inch barrel.

At this point I'm very frustrated, being that, this gun did not pierce primers before now, then again, it could be ammo related, but if it were so, the 4 of 50 magtechs I shot would not have shown anything as far as primer piercings are concerned. I say before now because I just got the gun back from S&W about a week or so ago, long story short, it went in for a bent crane, before going in, I went though 150rounds of .38 Special and 350 rounds of .357 without primer piercing although I did bleed from the ears on occasion as my ears catch shrapnel pretty good. Now, after only 100 rounds, I see pierced primers.

What should I do? On Tuesday I plan on taking it to the gun smith again and see what'll happen, but dang it with my luck something else will happen... At this point i just feel so exasperated... feels as if this gun is becoming one of those money pits...

Dan

 

[Majic]

If you reload or know a reloader just size and prime a few cases and fire them to check the firing pin.
Also examine the other cases fired to see if there was any primer flattening or cratering around the firing pin stikes. It sounds more like an ammo problem than a faulty handgun.

 

[Mike Irwin]

The first thing you should do is examine the firing pin nose.

Is it smooth, or is it rough, or possible chipped or even broken?

If it wasn't piercing primers before, and has done it only on the Milwall stuff, and the gunsmith checks protrusion and finds it to be within spec, you can pretty safely say that it's the ammo.

 

[Old Fuff]

Mike is right. This is far more likely to be an ammunition problem then the revolver. Try some different brands of cartridges and see if they pierce primers too.