is this a crack or mold mark?

[GR00VY]

I posted on a couple other forums and just trying to get some opinions. Let me know if you have noticed this on your M&P full size pistols.

I just recently bought a M&P 40 fs. I have about 250 rounds down it at this point. It shoots great. I have been shooting sigs a lot lately so I am not familiar with some of the polymer framed guns. I was cleaning the M&P tonight and noticed a crack (maybe) or some sort of mold mark in the frame I was wondering if anyone could explain to me.

You can see the part circled in red has a line running through it. Is that just part of the polymer frame and normal or is a crack developing?



It goes up the sides a bit on both sides.



I saw that the slide seems to be making contact with the front leading edge of that spot as well. You can see the scuff marks.


Not sure if normal or not and if these two things are related. Any insight would be helpful. Thanks.

 

[Kadonny]

Looks like a crack to me. When you run your finger over it, does it feel indented like a crack?

 

[AGoyette]

I am not an expert, but it looks like a crack to me. I would think that if it was a mold mark, the edges would not be jagged.

 

[Ofc.JL]

From the pictures, it looks like mold flaw/ fold. Without it in my hands, and a real close look, I cannot say for sure. Gently try to flex the frame in that area and see if it opens up any. If it does, good chance it's a crack, or a molding flaw that got by QC. I checked my '09 FS .40, and it has no mark. If anyone else out there has the same sort of mark on their .40's, please chime in.
And, of course, you can call S&W and return it to be examined. They will take care of you.
Ofc.JL

 

[snubbyfan]

Hard to tell from lookin' at a picture. Could either be a flow line or a crack. Either way, If I saw that as a rubbermaid tech., I'd reject it and tweak the molding press. Doesn't look to me like it belongs.
As AGoyette said, a mold line should be uniform not jagged.

 

[tdstout88]

My 40 compact has a mold line in the same spot, but it is very uniform and not jagged at all.

 

[Bkreutz]

Here's a picture of the same area on my 9L (same lower frame as a .40). Looks like the same (or similar) mark. This pistol has over 50K rounds through it so I don't think it's a structural problem.

 

[Ofc.JL]

Hmm. I will look at my other M&P's. It may well be a hot mold material fold over as the frame is ejected from the mold. If a lot of M&P's have it, then that's very probably what it is. And I am not the expert on plastics molding, I am just familiar with the process.
Anyone who does plastics moulding for a living want to take over, please feel free.

 

[GR00VY]

Here's a picture of the same area on my 9L (same lower frame as a .40). Looks like the same (or similar) mark. This pistol has over 50K rounds through it so I don't think it's a structural problem.

Yours it much more uniform than mine. See how yours follws the same line. Mine doesn't. I can see the faint line on mine where yours is but then in between that line and the edge I have the line pictured above. It doesn't split open if I Flex the frame. I emailed S&W but am not holding my breath on getting a response. I hardly ever get a response when I send emails. I am still waiting on a response from when I used to own an M&P 2 years ago.

 

[skip4309]

Hard to say but I'm blind...lol....use a jewelers loop or a big magnifying glass...or take somewhere that does non destructive testing...they put a florescent dye on it...then wash it off...and use a black light...the residue will stay in the crack or defective area and will show up under the black light if it is cracked....

 

[Rastoff]

It's not a crack. It's part of the injection molding process.

The slide does indeed impact the front of that part. However, that impact would neither cause nor exacerbate that crack. The forces are in a different direction.

Your path forward is clear; keep shooting. If the line changes, you have a lifetime warranty and they will replace the frame at any time. The directionality of that crack, and its location, will not cause a catastrophic failure so, there is no risk if injury from that should it turn out to be a crack.

I predict that there will be no change and it's just a mold mark.

 

[emory]

http://en.wikipedia.org/wiki/Flash_(manufacturing)

 

[emory]

Minor mold misalignment. Structurally harmless. Keep shooting.

 

[mjsmith1223]

Just took the slide off my 9c and looked. I have the exact same mark.

 

[GR00VY]

Thanks all for the feedback. After looking it over more and researching. It is for sure a molding mark. It is as on poster stated above, flashing. It is just left over plastic. I put oil on it and didn't absorb. I tried putting downward pressure on the front of the frame and it did not separate. Thanks for helping me figure it out. Great forum here.