It's not headspacing. It's timing. The bolt has to stay locked until the bullet leaves the barrel. The barrel/slide have to stay locked together until the bullet leaves the barrel. The problem is sometimes the round does not chamber correctly and the slide will go into battery BUT not all the way. When that round fires, the barrel will tilt down immediately and the slide will begin to extract the case while the system is still pressurized. That's when these bulges occur. Sometimes the case fails.
.40 S&W Bulge
- Thread starter m3mh0g
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918v; I was talking about MP5's causing bulges in the last post I made, the barrels don't move. It has a fluted chamber / delayed blowback system.
When I talked to the armorer he said he'd check the bolts. Evidently the bolt carriers in MP5's are hollow and contain tungsten balls that act as an anti-bounce device. If those get jammed up and don't move, the bolt can bounce BACK after chambering, so when the next round goes off, it won't be fully seated in the chamber.
When I talked to the armorer he said he'd check the bolts. Evidently the bolt carriers in MP5's are hollow and contain tungsten balls that act as an anti-bounce device. If those get jammed up and don't move, the bolt can bounce BACK after chambering, so when the next round goes off, it won't be fully seated in the chamber.
BisleyBlackhawk45
Member
I use a LEE factory crimp die with the innards removed. I push a .40 case all the way through the die from the bottom using a bullet sizing pusher (for sizing cast bullets). This full length resizes the case...from rim to head...and removes the Glock pregnant bulge. You Tube has some good videos on this. Search for "sizing glocked up brass". This works like a charm and can also work on 10 mm and .45ACP since they are straight wall cases.
weeniewawa
Member
I use the Lee Factory crimp die to do this too
they sell a kit to do this, only like $15 plus the FCD and this kit can be used with the 40,45 and 10mm FCD so you only have to buy one
they sell a kit to do this, only like $15 plus the FCD and this kit can be used with the 40,45 and 10mm FCD so you only have to buy one
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