S&W SDVE .40 unsupported chamber?

Interesting. I got rid of my SDVE series. Before i started to reload though. Still would be good to know.

Typically from glock 40's known as the glock smile. Well looks like the smith guns have it too from what you are saying.

The .40 S&W is a cartridge very subject to overpressure problems which in this case could be caused by the phenomenon of the bullet setback during chambering. Were the cartridges you fired during the session factory or reloaded?

I have a couple and neither has that issue, the only place I've ever seen the "smile" was at a competition, I've seen replacement barrels pre covid for reasonable prices, maybe if his has a problem you can find one, if he is the original purchaser it has a lifetime warranty.

I have an older 40VE. I haven’t noticed anything with the brass

I had a SD9VE. I shot Federal ammo FMJ and JHP and never had such a thing happen. The 40 and the 9 are very similar. I think it was an ammo issue not a gun issue.

I had one, over ten years ago and yes it bulged brass very badly, much worse than any Glock I've owned. That's actually why I got rid of it.

1942bull said:

I had a SD9VE. I shot Federal ammo FMJ and JHP and never had such a thing happen. The 40 and the 9 are very similar. I think it was an ammo issue not a gun issue.

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The 9 and 40 relative to the smile are not the same from what I have read. It is more prevalent with the 40.

I just did an Internet search on SD9VE 40 bulging casings. The bulging 40 casing syndrome is well documented on the two S&W forums. The syndrome is also reported on some 40 caliber FN and Glock pistols. Onereport was that S&W CS stated the was a normal occurrence. So I guess it is a combination of the chamber diameter v, the casing diameter coupled with the powere of the 40 rounds. I could find no reports of,a SD9VE having a similar issue.

If the gun is functioning otherwise fine then I wouldn't worry about it. I think Glock's newer .40S&W's have changed it but Glocks ran that way for a long time just fine.

Given how prevalent Glocks are and since I use range-pickup brass a lot, for .40S&W I always run finished rounds through a Lee "bulge buster" which smooths any potential bulges back out.

This talk made me check the feed ramp on my .40 S&W H&K USP40 pistol's barrel.
The feed ramp does not extend into the chamber so no smiley faces.

Try to chamber some factory ammo manually directly inside the barrel chamber and close the slide with just enough force to make the extractor engage the rim of the case. I know this is something that should normally be avoided, but it's just to make sure there isn't a bullet setback issue when the ammo is chambered from the magazine with subsequent overpressure issues. Shoot four or five ammo and watch the cases. If the smile in the cases persists it is a not fully supported chamber or a slight early opening of the slide during fire.

Encoreman said:

Hi 5-shots, why would there be overpressure issues with factory S&B ammo?

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Possibile bullet setback issue during chambering from the magazine. This is the third time I mention it... It is perhaps an unlikely but possible problem. In any case it should be definitively excluded by manually inserting some cartridges in the chamber, closing the slide (possibly without slamming it), firing and checking the cases.

Bullet set back would be due to using ammo with oversized throats and no crimp. Most NATO ammo controls that much more closely, and ammo makers are more than aware of the issue. Makers like Glock who used extended feed ramps had to deal with lawsuits over it, search "Glock kaboom" and see how old the problem is.

Ammo makers have to choose brass hardness to balance costs of forming it vs safety, and the extended feed ramps threw them for a loop early on. It would seem that those long ramps would actually set back a bullet less due to the flatter angle, and steep short ramps less so.

But, there's already a thread running on bullet setback elsewhere.

The cartridge could be crimped correctly according to the manufacturer's standards but the bullet setback could still happen due to the speed with which the slide goes into battery, the inclination of the feed ramp, the interaction between the feed ramp and the magazine, all things of this single example of SD40VE we do not know and which could be critical even if they do not compromise its functioning. We also know how much the .40S&W is subject to overpressure problems caused by its low internal volume. That's why I argue that some tests other than just load the magazine and fire must be done. Another simple test to check if the chamber is fully supported or not is to field strip the pistol, insert a fresh cartridge in the chamber and inspect if there's some room between the feed ramp and the case. At that point I would also try to insert one of the previously fired cases into the chamber to see how far it enters and where the smile stops. If it is verified that the chamber is fully supported, it is clear that the problem must be investigated in the direction of overpressure and/or early opening of the slide. It would also be helpful to fire the same cartridges with another pistol, side-by-side.

Did you take the barrel and do the plunk test. Should show you if it's supported or not.

I have the 40 VE, that I bought used and haven't fired it yet. So I was curious. Here is the M&P compared to the 40 VE.


There is a little difference in the chamber. I haven't had any problem with the M&P.

I'm hoping there won't be any problems with the VE.

kcofohio said:

I have the 40 VE, that I bought used and haven't fired it yet. So I was curious. Here is the M&P compared to the 40 VE.
View attachment 1021816

There is a little difference in the chamber. I haven't had any problem with the M&P.

I'm hoping there won't be any problems with the VE.

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Without a shadow of a doubt the M&P chamber is more supported (I would say absolutely fully supported) than the SD40VE chamber. The chamber of the SD40VE would seem in any case sufficiently supported not to give bulge problems but evidently in some cases it can give them.
It would be great if you post back your experience when you shoot your SD40VE.

The gun manufacturers don’t give a rip about your brass, so a bulge is not an issue to them. As long as you don’t get a ruptured case, your going to be fine. I wouldn’t consider reloading a bulged case, as it now has a weak spot in it. Shooting reloads will void your warranty, so manufactures don’t care about what the gun does to your brass. Comparing single loaded cartridges racked in slowly by hand, to auto loaded cartridges while shooting, is a very easy test, to eliminate a setback problem. If the compared brass looks the same, has bulge, then Its designed that way.

I've never noticed any bulged cases from mine but I can't say I've checked every single piece of brass either.

5-SHOTS said:

Without a shadow of a doubt the M&P chamber is more supported (I would say absolutely fully supported) than the SD40VE chamber. The chamber of the SD40VE would seem in any case sufficiently supported not to give bulge problems but evidently in some cases it can give them.
It would be great if you post back your experience when you shoot your SD40VE.

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I'm hoping this week or next for some range time. I'll report any findings.