Clean Powder but dirty brass?


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racine
December 12, 2010, 01:29 PM
I don't understand why my brass comes out dirty with powder residue on the upper half of the shell using Vithavourhi N 320-one of the cleanest powders you can find??? I'm loading 4.9-5.5 gr of this with 200 gr 45 ACP RN Moly bullets out of a polygonal barrel. I also use Fed. LPP. When I'm competing I load as much as 6.05 gr to make major power factor and still get some of that residue but not as much as the lower loadings. Any ideas???

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rcmodel
December 12, 2010, 01:35 PM
Blowing moly off the bullet base and it gets on the case before full sealing has occured??

Moly is nasty stuff that gets in all kinds of places it shouldn't.

And are these jacketed moly coated?
Or cast lead moly coated?
If the latter it's the bullet lube burning off.

rc

racine
December 13, 2010, 12:59 AM
I should mention that I shoot the exact combination in 40 SW out of a Glock 35 and my brass comes out clean. Same Moly bullets only in 180 gr, VV N 320 and Fed SPP. So what's the difference?

Funshooter45
December 13, 2010, 03:37 PM
Lower charge weights mean lower pressures. Every powder needs a certain pressure to burn most efficiently. When the pressure is too low, you get that sooty carbon buildup in your chamber and around the brass. Evidently, the 40 S&W round and chamber build up a higher pressure than the same amount of powder does in a .45. I don't do auto pistols, so I don't know those specifics. But it is universal that when you start dropping powder charges downward, you will eventually start getting that black soot on your casings. VV powders are indeed clean burning, but they are not immune to the laws of chemistry and physics. I use VV N330 for .45 Colt loads and it's the cleanest burning I have found, but I have to run it at a certain pressure.

You will also find that if you are shooting in cold weather, the cases get more sooty than they do in hot weather with the same exact load. It's the same reason, in cold weather the chamber pressure will be lower so the powder doesn't burn as efficiently.

Try increasing your powder weight just slightly until the soot goes away.

1SOW
December 14, 2010, 09:11 PM
I'm shooting light (1040'/sec) 125grJHP/FMJ 9mm loads and run into the same thing with n320. It's nowhere near as dirty/sooty as Win 231 at that speed , but my cases have soot on the top half. My feed ramp also picks up some soot but not bad.

It's 'cleaner than other powders I've tried, and I like the way it shoots.

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