I have been getting strange looking primer strikes on my speer range ammo (165 grain TMJ) The stikes is oblong (much like a glock) is this normal?? The firing pin/striker looks fine NO damage
thanks
1SG

if its what i am envisioning in my head, my FS 40 does the same thing with certain brands of ammo. never seen any problems so far.

Thanks for getting back to me so quick. Ya i was thginking the same thing with ammo. I find the Speer 165 graim TMJ to be very dirty ammo and not very accurate. The winchester on the other hand is good stuff. I did not dawn on me when i was shooting to check the winchester to see if the promer strikes are the same. I see your from Mass also
Thnaks Again
1SG

I reload my own ammo, but i have noticed it on new ammo as well. I thought it was a reload ammo only thing, but then i noticed on some new ammo as well. I usually buy the Winchester 100 packs from WallyWorld when i buy new ammo.

It is hard to be sure without seeing the fired primers of your ammunition, but it sounds like a firing pin drag mark which is caused by the barrel unlocking before the firing pin has fully retracted. It will appear somewhat teardrop shaped. This extremely common on locked-breech automatics, and the reason most have inertia firing pins that will retract under spring pressure immediately after strining the primer. It is an action timing issue that can be helped by loading down just a bit, or replacing the firing pin retractor spring with a Wolfe extra-power spring.

__________________
Gunsmithing since 1961

Hi Thanks
excellent observation and that is exactly the way the primer looks. Teardrop shaped and looks like the firing pin IS draging. will this cause harm to the weapon? cause malfunctions? you think a wolf spring is the cure?
thanks
again
1SG

Actually, S&W put a clearance cut on the breechface at the bottom of the striker hole in the breechface to minimize any shearing effect on the primer when the barrel unlocks (cratered primers have locked autopistols up if the circumstances are right). If you look at the breechface, you'll see a slight teardrop appearance to the striker hole.

So, the slight teardrop shape is intentional, as is the primer appearance. Don't try to fix what isn't broken.

BTW, if you look closely at the bottom of the slide, just to the rear of the breechface, you'll see a small debris hole that allows particulates that would otherwise collect in the striker tunnel to be pushed out by the normal action of the striker. Keep the hole clean.

Hi
Excellent observation and thanks for your input. I do notice the "teardrop' indent on the breachface. So this would explain the teardrop indentation on the primer? All all the M&P's the same way?
thanks again
Alex

The flaw to this being the cause is an "indent" in the breech face will not cause an "indent" in the primer. If anything a small bulge will be the result.

__________________
Gunsmithing since 1961

OK, Interesting so now what do i do? it has not effected reliability the weapon runs fine. Just thought it was odd.
thanks for all the input
Alex