S&W Shield .40 problem

[ftabangler13]

Hi guys, I just took a trip to the range to shoot a little bit and decided to finally test a magazine of my Winchester PDX1 Defender ammo out of my Shield .40 before practicing with some TulAmmo. I popped off 7 rounds of PDX1 in rapid succession, no fail to feeds, fail to ejects, no problems. I loaded up my Tula and went through all 50 rounds, no problems. On a whim, I decided to pick up one of the PDX1 brass from earlier and inspect it. To my surprise, there was a noticeable bulge in the brass near the rim cut where the feed ramp would be when chambered. I found 2 of the 7 casings and they both have this issue. I picked up a couple of the Tulas and there was not a bulge, but on a couple of them, there is a slight warping of the rim cut (hard to even see) in the same place right where the feed ramp would be. Has anyone else had this problem? Any suggestions? I will be calling S&W on Monday.

[puma guy]

Did you inspect the chamber for anomalies? Maybe the feed ramp is cut too far, i.e.too long compromising the chamber. Remove the barrel and insert a cartridge and see if it goes in the full length with no gaps where your are seeing the bulge.

[G.A. Heath]

Hi guys, I just took a trip to the range to shoot a little bit and decided to finally test a magazine of my Winchester PDX1 Defender ammo out of my Shield .40 before practicing with some TulAmmo. I popped off 7 rounds of PDX1 in rapid succession, no fail to feeds, fail to ejects, no problems. I loaded up my Tula and went through all 50 rounds, no problems. On a whim, I decided to pick up one of the PDX1 brass from earlier and inspect it. To my surprise, there was a noticeable bulge in the brass near the rim cut where the feed ramp would be when chambered. I found 2 of the 7 casings and they both have this issue. I picked up a couple of the Tulas and there was not a bulge, but on a couple of them, there is a slight warping of the rim cut (hard to even see) in the same place right where the feed ramp would be. Has anyone else had this problem? Any suggestions? I will be calling S&W on Monday.

The .40S&W is a high pressure cartridge, what you describe is often seen in Glocks and other firearms chambered in .40 S&W that lack a fully supported chamber. It is so common that at least one reloading die manufacturer has a "Bulge Buster" die set so that cases can be safely reloaded. If you are uncomfortable with it box it up and ship it to me and I'll ensure that it is properly "disposed of"...

[ftabangler13]

Did you inspect the chamber for anomalies? Maybe the feed ramp is cut too far, i.e.too long compromising the chamber. Remove the barrel and insert a cartridge and see if it goes in the full length with no gaps where your are seeing the bulge.

I dropped a PDX1 round into the barrel just now and it seated all the way around the barrel, but at the bottom, some of the case was exposed where the feed ramp came up. As long as its not something I REALLY need to worry about, I'm fine with it. Gun goes into battery no problem and like I said, I have not had any malfunctions whatsoever...yet.

[tomtexan]

The .40S&W is a high pressure cartridge, what you describe is often seen in Glocks and other firearms chambered in .40 S&W that lack a fully supported chamber.

I have experienced the same with my .40 S&W. It can be seen in this pic.

[ftabangler13]

I'm guessing since its so common that its not a big deal?

[G.A. Heath]

Its so common because its not a big deal. Take a look at a 9mm fired in a similar chamber, you will see similar, although much less pronounced, results due to the smaller diameter and unsupported surface area.

[OldCannon]

All chambers are technically unsupported to various extents. That is to allow proper feeding. Glock slightly modified their barrels some time ago, so you won't find the dreaded "Glock bulge" anymore (well, technically, you can, but no more than other 40 S&W barrels).