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Old June 9, 2014, 03:21 PM   #23
Unclenick
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Join Date: March 4, 2005
Location: Ohio
Posts: 21,022
The reason Hodgdon doesn't show 9 mm data for HS-7 is that it has been discontinued for some time, so the Hornady data will be old. HS-7 is a slower powder than HS-6, which would be more appropriate.


Birddseedd,

The actual cause of the problem is in your first photo. This old powder is too slow for your cast lead bullets, which have lower start pressures into the rifling than jacketed bullets do. As a result, your peak pressure is too low to produce complete combustion of the powder. The slower the powder is, the higher the pressure required to produce reasonably complete burning.

The above explains all those little unburned grains in your ejection port. I've had those jam up revolvers and self-loaders both. Your gun worked fine at first, simply because it was still clean enough to operate. With the unburned particles sticking to lube that was splattered around the inside of the gun during ejection, they are jamming the gun. Even with the lube gone, they may eventually jam it up again. The best bet is to switch to something that burns cleaner.
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