WrongHanded
Member
- Joined
- Jul 6, 2017
- Messages
- 4,771
...That is the question.
Well, I think I've answered it. And for me, the answer is not to crimp.
I've worked up some 124gr FMJ-FP bullets from RMR, with Power Pistol. For those who didn't see my last post of. 357 Sig, I just started reloading it.
The problem I had was actually with the Lee Factory Crimp Die. I use a FCD with all my other cartridges (though none are necked), because it's seemed the easiest thing to do. I made up a few mock rounds to make sure they'd pass a plunk test, and would cycle without any bullet setback. I kept getting setback, and kept applying more crimp. I finally got to a point where I decided the setback was not enough (with one cycling in the gun) to worry about, so I did the load testing for accuracy.
But it was still bugging me when I got back from my second round of testing. So instead of using the new Starline brass I bought, I resized a few once-fired Federal cases, and added crimp. Still failed to avoid setback. So the brass didn't seem to be the problem. Then I reinspected the necks of these cases, and compared them to some factory ammo.
I believe the crimp die has been pushing the brass down and somehow flaring the lower portion of the neck whilst crimping the top. So it's removing case tension from the bullet, in the area of the neck the die does not contact.
I'd already been putting an absolute minimum bell on the case mouth, just enough to get the bullet to sit straight during seating. So I just bypassed the FCD and tried cycling a dummy with a Federal case. No setback after repeated cycling. Then a new Starline case. Same thing. Success!
Maybe I've been crimping too much. The FCD instructions aren't terribly extensive. But in bold text at the bottom it says Be certain to give the lever a firm push at the end of the stroke to close the collet and apply crimp (25 lbs. minimum). So I assumed I was doing it right. The crazy thing is that on one dummy cartridge, I crimped it really hard. Cycled it through the gun a few times, measuring the OAL as it got shorter each time. Finally, the bullet ended up inside the case and rattling around loose. When I pulled it, it had a deep ring in the jacket. Yet it still managed to set back like that.
It's no crimp for me, from now on.
Well, I think I've answered it. And for me, the answer is not to crimp.
I've worked up some 124gr FMJ-FP bullets from RMR, with Power Pistol. For those who didn't see my last post of. 357 Sig, I just started reloading it.
The problem I had was actually with the Lee Factory Crimp Die. I use a FCD with all my other cartridges (though none are necked), because it's seemed the easiest thing to do. I made up a few mock rounds to make sure they'd pass a plunk test, and would cycle without any bullet setback. I kept getting setback, and kept applying more crimp. I finally got to a point where I decided the setback was not enough (with one cycling in the gun) to worry about, so I did the load testing for accuracy.
But it was still bugging me when I got back from my second round of testing. So instead of using the new Starline brass I bought, I resized a few once-fired Federal cases, and added crimp. Still failed to avoid setback. So the brass didn't seem to be the problem. Then I reinspected the necks of these cases, and compared them to some factory ammo.
I believe the crimp die has been pushing the brass down and somehow flaring the lower portion of the neck whilst crimping the top. So it's removing case tension from the bullet, in the area of the neck the die does not contact.
I'd already been putting an absolute minimum bell on the case mouth, just enough to get the bullet to sit straight during seating. So I just bypassed the FCD and tried cycling a dummy with a Federal case. No setback after repeated cycling. Then a new Starline case. Same thing. Success!
Maybe I've been crimping too much. The FCD instructions aren't terribly extensive. But in bold text at the bottom it says Be certain to give the lever a firm push at the end of the stroke to close the collet and apply crimp (25 lbs. minimum). So I assumed I was doing it right. The crazy thing is that on one dummy cartridge, I crimped it really hard. Cycled it through the gun a few times, measuring the OAL as it got shorter each time. Finally, the bullet ended up inside the case and rattling around loose. When I pulled it, it had a deep ring in the jacket. Yet it still managed to set back like that.
It's no crimp for me, from now on.
