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frumious · November 7, 2010, 10:37 PM

I have had intermittent problems for as long as I have been reloading (nearly two years now) with pistols failing to go into battery. It has happened with all of my autos I handload for. I have or have had some 9's (Sig P225, Sig SP2022, CZ 75 P07) and some .45's (Metro Arms 1911, Beretta PX4 Storm). I would get a couple problem rounds every box maybe. Although I could go for several boxes and not have any problems sometimes. Since it was so random I figured it was crappy range brass or gunk buildup in the guns or something. Well, it was none of those. It was a problem with my reloading technique. Two problems, actually.

The first problem had to do with the fact that I never really knew how to measure taper crimp firmness. I use Lee dies on an RCBS Pro2000, and I adjusted the factory crimp dies on my 9mm and .45ACP sets per the Lee manual. This ends up being "Blah blah blah turn down the FCD adjustment until you feel it hit the case, then turn it down half a turn more, then adjust to taste." I guess I thought firmness of crimp was measured in turns of the FCD adjustment screw...I wondered how I'd ever discuss crimp with folks who didn't have Lee dies

It wasn't until here recently when I read a thread on TFL that I realized I am supposed to measure crimp with my dial calipers on the very end of the completed cartridge, and then compare that measurement with what's in my reloading manuals. D'oh!! How about that! No mystery at all!

The second problem had to do with the fact that I had always been very conservative on COAL (usually using max spec or close to it). Thing is, I hadn't realized that the chambers of my pistols were not necessarily designed with respect to the shape of my particular bullets. Trying the "drop the completed cartridge into the barrel" test confirmed that I was indeed hitting the rifling. BUT I mis-interpreted these results initially. I thought the crimp was the problem...not enough crimp, the case mouth was catching somewhere as the cartridge chambered. I was determined that was it. So when I measured the crimp, and it seemed OK per spec, I tried increasing it a little more anyway. This caused MORE failures to go into battery.

It wasn't until I sort of went back to the drawing board and tried the drop-in test with an empty resized case that I realized the crimp was fine, and that the problem was the bullet. My cartridges were way too long. But since I hadn't been crimping very firmly, most of the time the bullets would seat in the rest of the way as the cartridges chambered, and all would be well. But sometimes they wouldn't, and I'd have to push the slide the rest of the way into battery with my thumbs

Fortunately I always use a powder charge in autos that's on the light side. So the extra seating depth (that I didn't know about!) wasn't hurting me any.

This is why increasing the crimp made the problem worse. The pistols were now having to work harder to seat the bullets the rest of the way.

So anyway, I have now learned that for my pistols, I need 9mm COAL to be about 1.100 and .45ACP COAL to be about 1.195. And I crimp at or a couple thousandths tighter than spec for both calibers. I use Precision bullets for both calibers - 125's (flat points) for 9mm and 200's (round nose flats) for .45ACP.

FWIW, I have also learned that it takes a WHOLE LOT of taper crimp to make a cartridge that is unable to headspace on its mouth. And it happens WAY after you start cutting into the bullet with the case mouth. So its pretty obvious.

So that's my COAL adventure story, and I'm sticking with it.

-cls

November 7, 2010, 10:37 PM	#1
frumious Senior Member Join Date: May 13, 2009 Location: Carrollton TX Posts: 521	Pistols not going into battery I have had intermittent problems for as long as I have been reloading (nearly two years now) with pistols failing to go into battery. It has happened with all of my autos I handload for. I have or have had some 9's (Sig P225, Sig SP2022, CZ 75 P07) and some .45's (Metro Arms 1911, Beretta PX4 Storm). I would get a couple problem rounds every box maybe. Although I could go for several boxes and not have any problems sometimes. Since it was so random I figured it was crappy range brass or gunk buildup in the guns or something. Well, it was none of those. It was a problem with my reloading technique. Two problems, actually. The first problem had to do with the fact that I never really knew how to measure taper crimp firmness. I use Lee dies on an RCBS Pro2000, and I adjusted the factory crimp dies on my 9mm and .45ACP sets per the Lee manual. This ends up being "Blah blah blah turn down the FCD adjustment until you feel it hit the case, then turn it down half a turn more, then adjust to taste." I guess I thought firmness of crimp was measured in turns of the FCD adjustment screw...I wondered how I'd ever discuss crimp with folks who didn't have Lee dies It wasn't until here recently when I read a thread on TFL that I realized I am supposed to measure crimp with my dial calipers on the very end of the completed cartridge, and then compare that measurement with what's in my reloading manuals. D'oh!! How about that! No mystery at all! The second problem had to do with the fact that I had always been very conservative on COAL (usually using max spec or close to it). Thing is, I hadn't realized that the chambers of my pistols were not necessarily designed with respect to the shape of my particular bullets. Trying the "drop the completed cartridge into the barrel" test confirmed that I was indeed hitting the rifling. BUT I mis-interpreted these results initially. I thought the crimp was the problem...not enough crimp, the case mouth was catching somewhere as the cartridge chambered. I was determined that was it. So when I measured the crimp, and it seemed OK per spec, I tried increasing it a little more anyway. This caused MORE failures to go into battery. It wasn't until I sort of went back to the drawing board and tried the drop-in test with an empty resized case that I realized the crimp was fine, and that the problem was the bullet. My cartridges were way too long. But since I hadn't been crimping very firmly, most of the time the bullets would seat in the rest of the way as the cartridges chambered, and all would be well. But sometimes they wouldn't, and I'd have to push the slide the rest of the way into battery with my thumbs Fortunately I always use a powder charge in autos that's on the light side. So the extra seating depth (that I didn't know about!) wasn't hurting me any. This is why increasing the crimp made the problem worse. The pistols were now having to work harder to seat the bullets the rest of the way. So anyway, I have now learned that for my pistols, I need 9mm COAL to be about 1.100 and .45ACP COAL to be about 1.195. And I crimp at or a couple thousandths tighter than spec for both calibers. I use Precision bullets for both calibers - 125's (flat points) for 9mm and 200's (round nose flats) for .45ACP. FWIW, I have also learned that it takes a WHOLE LOT of taper crimp to make a cartridge that is unable to headspace on its mouth. And it happens WAY after you start cutting into the bullet with the case mouth. So its pretty obvious. So that's my COAL adventure story, and I'm sticking with it. -cls Last edited by frumious; November 7, 2010 at 10:44 PM.