scooter123
Member
Look, at this point it's not possible to identify the root cause. BTW, I've seen references in this thread that the 40 S&W is a "very high" pressure caliber. The MAXIMUM pressure for the 40 S&W is 35,000 psi, only somewhat higher than the 9mm parabellum at 34,084 psi. IMO while the 40 S&W is a rather high pressure caliber I don't think that it even approaches excessive and will point out that the casing was DESIGNED for this level of pressure. Basically I consider this event an aberation instead of an expected consequence of the pressures involved.
In this case I do NOT think that setback can be suggested as a cause. The reason I say this is that the measurements posted for the remaining cartridges do not suggest that there is any setback at all. The variation in lengths posted is completely normal for almost any commercial ammunition on the market. BTW, I have checked because when I first started shooting the 40 S&W I too was concerned about reports I saw on setback. Winchester Ranger T, Speer Gold Dot & Lawman, Federal, Remington, and Hornaday all exhibit similar variations in OAL when you put a set of calipers on a brand new box.
However, as Glock found out the 40 S&W does require a certain amount of support in the chamber. All those blown up Glocks that we've all read about typically took place early on in the design cycle of the particular model in question. I think it was a result in Glock tending to place feed reliability a bit to high on the priority list and as a consequence used a feed ramp design that took away too much support for the cartridge. In addition it's also likely that some of those case blow outs occured with reloaded ammo that had too many cycles on the brass. To be blunt, I don't think that it's wise to reload brass that has been fired in a Glock more than 3 or 4 times. Brass does work harden and does get brittle as a result.
Point is the chamber in the Shield may not provide enough support for the 40 S&W. If that is the case we will be seeing a lot more posts about blown up 40 caliber Shields. That is an inevitable result when a chamber is designed without adequate support.
Second possibility is a timing fault. Basically, the extraction process started before pressure in the casing dropped below unsafe levels. It you start pulling a casing while the pressure is sky high the normal mode of failure is for the case head to pull off the casing as pictured. The most likely cause for this type of failure would be a broken or severely shortened recoil spring. Since this was a brand new pistol I think it's highly unlikely the shooter used a cutoff wheel on the recoil spring. That leaves a broken recoil spring, which can happen if the spring wasn't heat treated properly. If that is the cause we will probably see a recall for recoil springs in the near future because they are normally heat treated in large quantities as raw wire, not one at a time.
Final cause is a bad round of ammunition. IMO this is the root cause. Basically I think that you had the bad luck to encounter a defective casing. It can and does happen and with the billions of casings that an outfit as large as Winchester makes every year it's a testament to their quality that it doesn't happen more often. Keep in mind that one Billion is equal to One Thousand Million. This means that a One in One Million failure rate would result in One Thousand failures for every One Billion sold.
That is an issue that can be layed at the feet of Corbon and I would not be surprised if they were willing to pay for the cost of replacing this pistol. Unfortunately, in this case we have ammo that wasn't accompanied by it's lot number or date of manufacture. With a large outfit like Winchester or Federal you'd probably be told to take a hike. However, Corbin is still relatively small and family owned so they may feel a closer link to the shooting public and exhibit a greater sense of responsibility for their product than one of the Majors. You really do need to get Corbin involved in this and if possible have Corbin talking to the techs at S&W.
In this case I do NOT think that setback can be suggested as a cause. The reason I say this is that the measurements posted for the remaining cartridges do not suggest that there is any setback at all. The variation in lengths posted is completely normal for almost any commercial ammunition on the market. BTW, I have checked because when I first started shooting the 40 S&W I too was concerned about reports I saw on setback. Winchester Ranger T, Speer Gold Dot & Lawman, Federal, Remington, and Hornaday all exhibit similar variations in OAL when you put a set of calipers on a brand new box.
However, as Glock found out the 40 S&W does require a certain amount of support in the chamber. All those blown up Glocks that we've all read about typically took place early on in the design cycle of the particular model in question. I think it was a result in Glock tending to place feed reliability a bit to high on the priority list and as a consequence used a feed ramp design that took away too much support for the cartridge. In addition it's also likely that some of those case blow outs occured with reloaded ammo that had too many cycles on the brass. To be blunt, I don't think that it's wise to reload brass that has been fired in a Glock more than 3 or 4 times. Brass does work harden and does get brittle as a result.
Point is the chamber in the Shield may not provide enough support for the 40 S&W. If that is the case we will be seeing a lot more posts about blown up 40 caliber Shields. That is an inevitable result when a chamber is designed without adequate support.
Second possibility is a timing fault. Basically, the extraction process started before pressure in the casing dropped below unsafe levels. It you start pulling a casing while the pressure is sky high the normal mode of failure is for the case head to pull off the casing as pictured. The most likely cause for this type of failure would be a broken or severely shortened recoil spring. Since this was a brand new pistol I think it's highly unlikely the shooter used a cutoff wheel on the recoil spring. That leaves a broken recoil spring, which can happen if the spring wasn't heat treated properly. If that is the cause we will probably see a recall for recoil springs in the near future because they are normally heat treated in large quantities as raw wire, not one at a time.
Final cause is a bad round of ammunition. IMO this is the root cause. Basically I think that you had the bad luck to encounter a defective casing. It can and does happen and with the billions of casings that an outfit as large as Winchester makes every year it's a testament to their quality that it doesn't happen more often. Keep in mind that one Billion is equal to One Thousand Million. This means that a One in One Million failure rate would result in One Thousand failures for every One Billion sold.
That is an issue that can be layed at the feet of Corbon and I would not be surprised if they were willing to pay for the cost of replacing this pistol. Unfortunately, in this case we have ammo that wasn't accompanied by it's lot number or date of manufacture. With a large outfit like Winchester or Federal you'd probably be told to take a hike. However, Corbin is still relatively small and family owned so they may feel a closer link to the shooting public and exhibit a greater sense of responsibility for their product than one of the Majors. You really do need to get Corbin involved in this and if possible have Corbin talking to the techs at S&W.
