tpelle
Bearcat
Interesting topic.
My understanding is that the .40 S&W was simply a shorter version of the 10mm, or alternately you could think of it as a "fat" 9mmP. Because of the shorter length of the cartridge relative to the overall length, the .40 cartridge tends to angle itself more nose-up than does a 9mmP in the same size frame pistol during the feed cycle. This sometimes caused issues when the pistol manufacturers "re-chambered" 9mmP pistols to make a .40S&W model. On Glocks, for instance, they had to relieve the bottom of the barrel chamber at the feed ramp, to keep a workable angle on the feed ramp, in order to get the stubby .40 to feed. The result was a chamber that only marginally supported the case head of the .40 cartridge.
A local city police department had gone from S&W 3rd generation pistols, which were getting a little worn, for Glock 22's. One day one of their lieutenants was shooting his Glock at the range for qualification when he had a case rupture, which ballooned the grip area of the Glock to the point that his middle finger on his right hand was broken. They picked up and examined cases on the floor of the range and found that all of the .40S&W cases fired from the broken Glock and those from the other officers qualifying, and found that a significant number of the cases showed signs of bulged cases just in front of the case head.
They traded in the Glocks for some model of SIG in 9mmP.
A friend of mine converted his Glock 23 to 9mmP by simply swapping the barrel and possibly the recoil spring. Says that it's much more pleasant to shoot.
My understanding is that the .40 S&W was simply a shorter version of the 10mm, or alternately you could think of it as a "fat" 9mmP. Because of the shorter length of the cartridge relative to the overall length, the .40 cartridge tends to angle itself more nose-up than does a 9mmP in the same size frame pistol during the feed cycle. This sometimes caused issues when the pistol manufacturers "re-chambered" 9mmP pistols to make a .40S&W model. On Glocks, for instance, they had to relieve the bottom of the barrel chamber at the feed ramp, to keep a workable angle on the feed ramp, in order to get the stubby .40 to feed. The result was a chamber that only marginally supported the case head of the .40 cartridge.
A local city police department had gone from S&W 3rd generation pistols, which were getting a little worn, for Glock 22's. One day one of their lieutenants was shooting his Glock at the range for qualification when he had a case rupture, which ballooned the grip area of the Glock to the point that his middle finger on his right hand was broken. They picked up and examined cases on the floor of the range and found that all of the .40S&W cases fired from the broken Glock and those from the other officers qualifying, and found that a significant number of the cases showed signs of bulged cases just in front of the case head.
They traded in the Glocks for some model of SIG in 9mmP.
A friend of mine converted his Glock 23 to 9mmP by simply swapping the barrel and possibly the recoil spring. Says that it's much more pleasant to shoot.