Firing Pin Impression - Problem?

BigBoy99

BigBoy99

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This past weekend I was out shooting with my brother-in-law. He is into the modern handguns while I like my C&R handguns. We were shooting his S&W M&P Compact in .357 SIG caliber and I was examining the firing pin impression on the fired cases. I thought the impression looked "weird" when compared to the impressions I get from shooting my WWII handguns. The pictures below shows the impression and I have two areas of concern. All of the rounds fired exhibited the same impression.

The red arrow marks a area which is below the firing pin. This is caused by the hollow area under the firing pin hole on the slide and is marked by the yellow arrow. I can't think of any reason why there would be this hollow area on the slide face. Is this something which is found on new handguns? To me it looks like a manufacturing error where a tool slipped and made a gouge.

The green arrow marks a "scuff" area which I can not figure out what would make such a mark. Perhaps the firing pin is still protruding when the case is ejected? Does anyone who is familiar with modern handguns have an explanation for these weird firing pin impressions?


I have posted this question on another site but have ignited a fire storm about the "quality" of striker fired hand guns. All I want to know if this is "normal" or is there a problem which needs to be corrected?





 
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I don't have my MP9 right now for compairson, it's at S&W for an unrelated reapair, but I've never seen anything like that in any gun.

My educated guess. (Redacted...apparently the firing pin hole in the breech face is teardrop shaped.)

Thanks Tonesurfer for clearing this up. See his post further down.
 
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My M&P 9 FS is nothing like that.

You can remove the slide and use a tool to depress the striker block, then use your finger or another tool to move the striker forward (like when it fires) and the tip will protrude from the slide. See if it's deformed.

If you're up for it, go watch a few vids on Youtube and see how to remove the striker for a closer inspection.

EDITED: Well, I just took a closer look at mine and it does have the teardrop. Not sure why I didn't notice before.
 
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My M&P 9c was made in 2008 but as far as I know the M&Ps have always left sort of a tear drop mark on brass.

Years ago it was explained to me that it made it easier for the brass to slip off the breach face during ejection. That may or may not be the reason, but the breach face looks normal to me.

Most pistols I own have their own distinctive brass impression on the primer. I don't have an M&P pic but here's the difference between a Glock and a Beretta.


Dave
 
My 9FS looks like that too. I'm not really concerned. So it's not an exact hole. Looks to me like it may have been designed to allow gunk from striker hole a place to go. Possibly to promote any gun oil drainage from the hole during cleaning so it doesn't stay up against the primer during loaded status? Just my thoughts.
 
The tear drop is normal and not a defect. All M&P semi's have them. It allows for cycling when the striker has not completely retracted as shown in the OP's picture.
 
All the M&P's have that teardrop feature. It's been discussed here numerous times. Nothing to worry about. I just grabbed a handfull of casings from my reloading tub and they all have both of those marks you pictured.
 
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Both red arrow and green arrow are normal.

Red arrow is primer material filling into the relief cut under the striker hole.
Green arrow is "primer smear" and is caused by the primer being drug across the tip of the firing pin during ejection process. Striker pin is not yet fully retracted and still in contact with the primer but the barrel has unlocked and is hinging downwards.

Both are normal, carry on, nothing to worry about.
 
tonesurfer said:
Both red arrow and green arrow are normal. Red arrow is primer material filling into the relief cut under the striker hole. Green arrow is "primer smear" and is caused by the primer being drug across the tip of the firing pin during ejection process. Striker pin is not yet fully retracted and still in contact with the primer but the barrel has unlocked and is hinging downwards. Both are normal, carry on, nothing to worry about.
Click to expand...

Thanks for clearing this up. Like I said my Shield is at SW for repair...and I had never seen anything like this before. And, I've looked at a lot of brass from other brands. My Shield started dropping mags right after I purchased it. So, I didn't look at the ejected brass.

I wonder what the wear rate is on the firing pin when it drags across the primer face.

Live and learn. Anyways, like I said, thanks for setting things straight. I'll look at my brass as soon as I get my gun back and have a chance to get to the range. They're replacing it and it will be at least...at least...2-3 weeks before they have a gun to ship.
 
Ed911 said:
I wonder what the wear rate is on the firing pin when it drags across the primer face.
Click to expand...

I have over 13K rounds thru my M&P 9c purchased at the end of 2008 and still use the original striker.

There were non-related striker issues in that time period so I bought a spare but have never had to use it. The entire head (not the tip) was snapping off on some models.

Dave
 
As I said, since I've never seen such a primer strike pattern, I was curious if it was something which has been developed for the newer generation of handguns (which it has!). I guess I'm just use to seeing the round primer strike from my C&R WWII pistols and though I'd ask.

I really appreciate the information obtained. Thanks.
 
BigBoy99 said:
As I said, since I've never seen such a primer strike pattern, I was curious if it was something which has been developed for the newer generation of handguns (which it has!). I guess I'm just use to seeing the round primer strike from my C&R WWII pistols and though I'd ask.
Click to expand...
Jumping in late, but...
Are most of your C&R pistols Blow-back (like my WWII P38 and even my later manufacture P64), or are some Lock-Breach?
 
RobzGuns said:
Jumping in late, but...
Are most of your C&R pistols Blow-back (like my WWII P38 and even my later manufacture P64), or are some Lock-Breach?
Click to expand...

The P38 is a locked breech handgun. The Walther PP and PPK are blow-back.

I'm thinking of my Colt M1911A1 made in 1943.
 
Search for primer smear, primer swipe. That is just a couple of names this is called. Firing pin still sticking into the primer as the chamber drops.

Bob
 
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