Pierced primers

[38SPL HV]

I have an excellent condition S&W Mod 28 which pierces primers even Remington 38 Spl +P's on occasion. It has done it with reloads also in 38 Spl and +P's with both Winchester and Remington primers. My 357 Magnum loads don't exhibit the same issue even at their higher pressures - I'm stumped on this one.

I also have the strain screw all the way in and reluctant to back off and loosen it since it did create some FTFs in the past.

Any help or ideas are greatly appreciated

Thank you

 

[MichiganScott]

Check the firing pin nose. Often when you start piercing primers the gasses will pit and/or sharpen the tip. Then you start piercing more primers and the condition becomes worse.

 

[Tired Gunsmith]

suggest replacing the firing pin with a NEW one

 

[Hapworth]

Check your headspace to make sure you're in spec. Keep your strain screw well-seated -- they're not meant to be mainspring tension adjusters.

 

[armorer951]

To go along with what others have said, check to make sure that the hammer nose is "free" in the hammer, and is not bound up with corrosion or old lubricants, etc. There should be some movement of the nose up and down in the hammer. The hammer nose should also be spring loaded. (the tiny spring could also be damaged or corroded)

Take a look at the hammer nose bushing also, as it may be damaged or the hole elongated.