sd40ve 6 o'clock bulge

[guntotingpuertorican]

i have some empty cases from winchester 165 grain white box with no bulge today i shot 50 rounds of american eagle 180 grain and 50 rounds of privi partizan 180 grain hp and they bulged a little is this normal in different grains?

the one on the right not bulged and is win 165 grain

the one on the right win 165 rest ppu 180 and american eagle

 

[retired_diver]

IMO the 40SW seems to be a cartridge that has a tendency to bulge. With a Sami pressure of max 35k it can and does expand the case.


this is a pic of a just shot 40sw notice it will not fit into the Lee Factory gauge; of course that is why we resize it.


Here is a pic of a resized 40sw that had been shot in a glock 23. Notice the infamous "glocked" bulge. Notice the bulge is completely around the cartridge. It can be removed for reloading with a push thru Lee or Redding die.
The glock has a non-fully supported barrel and always has a bulge.
Even our fully supported barrels are not exactly fully supported as you have seen in your own pictures. Your pictures show a localized or spot bulge most likely where the extractor grabs. So based on how much annealing (strength) a manufacture puts in the case and how hot they load it, you see the results.

 

[Aladinbama]

I just asked a similar question without searching to far into threads here. This is the response I received from S&W;

Dear Customer,
This is part of the design to ensure reliability of feeding.
If further assistance is required please reply accordingly.
Sincerely,
Rob

The bulge only occurs above the feed ramp (at 6:00) and if you disassemble the firearm and play with a spent casing and the barrel it will go completely in the barrel at that position. It won't got more than about half anywhere else. I don't really like it, but ...

 

[frankmako]

this is normal and will not cause any problems. the bulge is like the one you have in the glock 40 guns. all my glocks factory barrels will give you a bulge because the barrel does give a full support of the case at the six o-clock area. this lack of full case support is need some so the round will load without stove piping. the sigma bulge is not as bad a the glock 40 bulge.

 

[guntotingpuertorican]

thanks for all the replies and pictures i was a little worried!

 

[Ofc.JL]

And remember, Guys, the .40 S&W round has no +p because it already is loaded at +p pressure, like RETIRED DIVER said. Part of the problem stems from geometry. A straight wall case such as the .40(relatively speaking) must have some clearance to transition the turn up into the chamber. The cartridge itself doesn't bend, so the chamber has to have an angled "break" area, just at the top of the feed ramp. This lets the cartridge radius the turn and line up with the chamber. End result is a small lack of support just at the end of the chamber. Virtually all auto pistols have this, in .40's it's rather obvious because we see the bulge in the case due to the higher pressure of the cartridge. .40 cases are thicker in the web area than other cases just for this reason.
It's very normal. I am not crazy about it, either, but it's the "Nature of the Beast", so to speak.
Thx, be safe.
Ofc.JL

 

[DanielF]

And remember, Guys, the .40 S&W round has no +p because it already is loaded at +p pressure, like RETIRED DIVER said. Part of the problem stems from geometry. A straight wall case such as the .40(relatively speaking) must have some clearance to transition the turn up into the chamber. The cartridge itself doesn't bend, so the chamber has to have an angled "break" area, just at the top of the feed ramp. This lets the cartridge radius the turn and line up with the chamber. End result is a small lack of support just at the end of the chamber. Virtually all auto pistols have this, in .40's it's rather obvious because we see the bulge in the case due to the higher pressure of the cartridge. .40 cases are thicker in the web area than other cases just for this reason.
It's very normal. I am not crazy about it, either, but it's the "Nature of the Beast", so to speak.
Thx, be safe.
Ofc.JL

This post has set my mind at ease!! I just bought a SD40VE a month ago. I normally buy 9 but wanted to try 40 and this pistol fit the bill. I've put 270 rounds threw mine and it bulged quite a few of them. I thought that this just had to be a 40 thing and this thread has confirmed it. I'm guessing if we just stick to factory ammo we shouldn't have much to worry about. Thanks for the info!!

 

[dajogejr]

. I'm guessing if we just stick to factory ammo we shouldn't have much to worry about. Thanks for the info!!

Not true. Just a quality reload. I have over 1k trouble free rounds through my sd40ve, not a single round fired was factory new.