M&P Shield 9 going back to S&W. Again

[Astocks2622]

I bought a brand new Shield 9mm in September 2013, & it bulged my brass terribly. As in beyond salvation for the reloader. It looked to me that the feed ramp was cut too far into the chamber. I sent it in, & when I got it back, the paperwork said they'd "modified" the barrel. Not sure how you can modify an improperly machined barrel... Anyway, it still bulges my brass. Can't tell any difference. Light reloads, factory ammo, +p SD ammo. about 60% of the brass that goes thru the gun bulges, & 90% of the +p...

guess it's going back yet again, & I'll be specifically asking them to replace the barrel, & shoot some +p out of it...

the real bummer is that the gun is far more accurate than I. this is an 8 shot (full mag) string from 7 yds.

hope they can get it fixed.

 

[Rastoff]

Nice shooting.

Yep, it sounds like you need a new barrel. Did you take any pictures of a round in the chamber? I'd like to see how well supported it is. Did you take any measurements of the chamber?

 

[Astocks2622]

thanks!
I'm currently out of town, so don't have access to my calipers, but I'm not sure what measurement would be indicative of a problem. just measure depth to the lands at the top of the chamber & then at the bottom of the chamber to show chamber encroachment? When I get home next week I can get some measurements.
here's a pic of the round in the chamber.

 

[Rastoff]

I've tried to get a good pic of a round in my 9mm barrel:

It looks to me like you are right and the feed ramp is cut too far back on your barrel. Thus, the round is not as supported as it should be. At least yours looks less supported than mine to me.

As far as measurements are concerned, I would at least measure the chamber diameter. If the chamber is too large it will cause the bulged casings like you're seeing. This is the SAAMI specs for a 9mm:

I believe the chamber diameter should be .395" +.010". So, if it's larger than .405" at the chamber mouth, it's too large. If it's smaller than .395" then it's too small, but that won't be the case with yours.

 

[Astocks2622]

yeah, comparing the profile of the feedramps also seems to indicate that mine is cut too deeply. My pics don't show it as well, but look at the sides of the ramp. yours has clear flats. mine is almost a knife edge.

also, looking at that drawing, wouldn't the chamber be .391 +.010? the .394 should be the rim, which doesn't go in the chamber, right?

 

[Rastoff]

also, looking at that drawing, wouldn't the chamber be .391 +.010? the .394 should be the rim, which doesn't go in the chamber, right?

Well, I don't know the exact dimensions for the chamber, but I would imagine they would make them at least .003"-.005" larger than the round. So, about .395" +.010" (which is the standard tolerance on that sheet) seems about right to me. I could be wrong.

Let me go measure mine and see what it comes to.

EDIT:
OK, I measured my chamber at the breech with my ultra high dollar ($25) digital calipers that I haven't calibrated in at least two years (I am a Metrologist by trade so I really did calibrate my calipers), and got a measurement of .391". So, I concede that it may indeed be .391" for the chamber at the breech end. In all honesty, any difference of .005" or so won't make any difference to the casing. That miss-cut feed ramp is another issue altogether.

 

[Rastoff]

If you like, I'll send you that picture if you shoot me an email. You can use this to send to S&W to illustrate your concerns. [email protected]

 

[Astocks2622]

yep, that sounds right. I'm an aircraft mechanic by trade, so my calipers (also around $25) are calibrated yearly... we'll see what it is when I get back into town.
thanks for the offer to email the pic. The one you posted here was big enough for me just to save a copy of it I'll keep you posted on what action S&W takes & if they fix the problem.

 

[mtnwinds]

Astocks2622, your chamber has been destroyed by someone who did not know what they were doing. No way would I fire a round in that barrel.

 

[trophyhunter]

Astocks, has the nickel plating or case actually split on those bulged fired casings!? I can't believe they had that and sent it back that way.

 

[Astocks2622]

yeah, well the info that came back with the gun the first time was pretty vague as to work performed. there was simply a box marked "barrel modification". I called S&W to get some clarification, but the CS person I got said that the smith just has a computer code system for reporting work done. it's not a written log. so they might have actually done some work to the barrel, or they may have replaced the barrel, & that was the computer code the smith used. so basically, even S&W doesn't know for sure what they did last time.
That's why I'll be specifying exactly what I want done.

 

[The Sarge]

I would send that pistol back with a few spent cases of factory ammo to show the bulge. Also tell them to fire the pistol and check the results. That is a catastrophic failure/kaboom waiting to happen and stress to them it is a safety issue and the liability is on them. That should get results. If they can't correct the problem S&W owes you a new pistol. Bill

 

[Astocks2622]

That's what I did the first time... I guess I'll just have to be more emphatic.

 

[Rastoff]

I would ask for a new barrel. Unfortunately, the decision on what to do is up to them.

 

[OakleyFreak]

Odd

My Son and I just got 2 new Shields 9mm
I bought mine at the local Gander Mountain
We got his from a dealer here on the forums.

Now My spent shell that came with the pistol looked good
My sons on the other hand had a bulge.
needless to say, this put us on alert for todays shoot.

Both guns spent brass, that bulges like this
We put about 50 rounds each thru the guns.
We collected 23 rounds of his 13 had a bulge and 10 looked ok
So 50/50

Guns shot as expected. we are happy from that standpoint.
My son is setting up to clean them now.

So you can see at the bottom of the chamber it is coated with gunpowder residue where the shell bulges. This is on both pistols

 

[Astocks2622]

S&W just sent me a shipping label for me to send it back to the mothership again. We'll see what they do.

 

[OakleyFreak]

S&W just sent me a shipping label for me to send it back to the mothership again. We'll see what they do.

Well I am not feeling all Warm and Fuzzy
My son is the Fire arms connoisseur of the family.
After looking at your post, he has determined that the barrels are flawed to say the least. He is not very happy.
he refused to clean the guns until I get a course of action

So I will be waiting to see what happens on your end
But I may also contact S&W too see what they say.
But Im not holding my breath.
And If this is a Barrel Flaw like we suspect, this will be the LAST S&W I ever own

 

[Astocks2622]

feel free to steal the photos to make your case with S&W, though it shouldn't be hard if you email them a pic of your bulged brass... I'm really hoping they just replace the barrel & everything's hunky-dory after that.

 

[OakleyFreak]

feel free to steal the photos to make your case with S&W, though it shouldn't be hard if you email them a pic of your bulged brass... I'm really hoping they just replace the barrel & everything's hunky-dory after that.

That would be nice
Im doing more research, seems like the squeaky wheel gets the grease.
But I must admit, if this is S&W new quality procedure. I am not impressed. For every 10 that look there are probably 100 that dont. never seeing or caring about the bulge in the brass
The whole thing is really starting to PISS me off.!!!!!!!

 

[OakleyFreak]

Well my son and I took the guns to the range today
we shot 100 rounds of freedom munitions 115 grain fmj. reloads
both guns ran flawlessly and no bulged brass
no FTE or FTF
I will try some 124 grain from gander mountain next weekend and see what happens ,but it may be the ammo I had that was causing the bulged brass