Are blackened cases a problem?


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slowr1der
March 8, 2012, 05:30 PM
I've been loading 9mm rounds with a 124 grain FMJ and 5.4 grains of Power Pistol and they shoot extremely accurately. However, after firing the outsides of the cases are really dirty. Is this a problem? I'm reading on here now that it's caused by too low of a pressure. Do I need to step up my charge, or am I ok like this?

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Waywatcher
March 8, 2012, 05:58 PM
Sounds like low pressure for sure.

That is below the starting load in my Speer Manual #14 (5.6 to 6.4)

I would bump it up .2 to .4 and try again.

rcmodel
March 8, 2012, 06:00 PM
Older alliant data says 6.6 is MAX with a 125 FMJ.
So a 10% reduction Starting load would be 5.9.

rc

ranger335v
March 8, 2012, 06:09 PM
"Are blackened cases a problem? "

Only in the mind of the beholder. Smoked cases actually help carbide sizers work better, that was the way they were originally intended to be used. But then the fad of polishing cases to a jewelery-like glitter came along and reality got lost.

Waywatcher
March 8, 2012, 06:15 PM
Well, there are dirty cases, and there are blackened cases.

I've seen dirty/sooty cases, and I've seen blackened cases from mousefart .45 Colt/Titegroup loads.

In my opinion, blackened cases are a problem. Dirty/sooty aren't necessarily.

Rule3
March 8, 2012, 06:40 PM
PP should leave a greyish light colored "soot" on the brass.

Speer lists for 124 gr 5.6 to 6.4 at 1.135

Hornady lists 4.3 to 5.7 at 1.150

I do not see that much difference in the bullets to warrant that extreme spread in charges(between the two manuals) for a FMJ RN other than the seating depth,

I use 5.2 at 1.150 and have no issues.

slowr1der
March 8, 2012, 06:47 PM
The Hornady manual is what I'd been going by. I wonder if I need to step up the load a little. I don't know if blackened cases are what I'm getting, or just dirty cases. The outside isn't covered in black soot, but the outside of the cases are dirty after firing.

kingmt
March 8, 2012, 06:57 PM
OAL makes all the difference.

kyshootingguy
March 9, 2012, 04:29 PM
I am fairly new to reloading, but I am using the same as the OP but with a cast bullet. Power Pistol with 125gr RN cast bullet. They are extremely accurate.

blarby
March 9, 2012, 04:34 PM
Are blackened cases a problem?

Yup,

Sooty brass is fugly.

I get my fair share of blackened cases using Unique in 45acp...but they function well.

Hondo 60
March 9, 2012, 06:16 PM
Depends on where that "blackened" area is...

If it's around the outside of the primer cavity, YES, that's a problem.
That means gasses are escaping around the primer.
That's not good.

If it's at the projectile end, then no, that's pretty normal.

barstoolguru
March 9, 2012, 07:14 PM
it could be a sign of too much heat that could weaken the case

ljnowell
March 9, 2012, 07:24 PM
it could be a sign of too much heat that could weaken the case

doubtful.

Blue68f100
March 9, 2012, 07:29 PM
If the soot is around the outside mouth area, it indicates low pressure and not sealing off good. Is it harmful, NO, just cosmetic. Jumping the load up will clear it up and make your gun action a little faster. Some powders are just dirty too, no matter what you do. But if your shooting lead, it comes with the lube.

helotaxi
March 9, 2012, 08:08 PM
If the gun functions reliably and the load is accurate...

If it ain't broke...

rfwobbly
March 10, 2012, 12:32 PM
Is it a danger? No. Is it optimal, well....

1) As has been said, black soot around the case mouth means that the pressure is not high enough to expand the case mouth and thereby seal the rear of the chamber. This means you're at a low pressure and loosing what little pressure you have to leaks. This is much like trying to water your garden with low water pressure and discovering your hose is leaking. What would you do?

2) Black soot also means the powder is not burning efficiently. When you burn most any fuel and you get soot, that's not really a very good thing. That's why candle wicks get trimmed, why kerosene lamps get their wick height adjusted, and why carburetors sometimes need adjustment. The best use of the fuel (in this case gun powder) is when it burns efficiently (cleanly).

By "efficiently" I mean that you get to use most of the energy you are paying for. This is much like a car that gets 18 MPG, when similar models get 30 MPG. Both owners get where they are going, but one gets more performance out of his fuel.

Since there are no adjustment knobs on the side of your cartridge, you have 3 choices:
1) Do nothing, 2) Add more of the same powder to raise the pressure (and thereby the efficiency), or 3) change to a powder that burns more efficiently at a lower pressure (IOW a "faster" powder). This is where a "powder burn rate" chart comes in handy.

Here's a serial burn rate chart I trust.....Right Here (http://www.hodgdon.com/burn-rate.html)

Here's a relative burn rate chart that is not 100%, but none the less very informative in its presentation.... Right Here (http://www.lapua.com/upload/reloading/reloadingburningratechart2011.pdf)


Hope this helps!

Fishslayer
March 10, 2012, 01:38 PM
Blackened outside is fairly normal for low power loads. The brass doesn't expand enough for a complete seal. My mousefart .45ACP generally have a nice black streak down one side.

Master Blaster
March 10, 2012, 01:54 PM
How does it shoot out of your gun? If the load is accurate and the velocity is high enough for what you want to do, you can either not worry about it, or use a faster buring powder.

Power pistol may have a bit more flash than is acceptable for self defense loads at full power.

Blue68f100
March 10, 2012, 07:40 PM
If your recoil sensitive just bump it up 0.1gr for awhile then do it again at a later time till you get it burning clean or reach max. Some powders are inherently dirty no matter what the load. Doing it in small changes over time you will not hardly notice it. Or the other option would be to shoot a gun that has a lot of recoil (357 Sig, 357 Mag, 44 mag you get the idea), and your loads will feel like a 22short.....

il.bill
March 11, 2012, 01:29 AM
rfwobbly

Thanks for the links to the burn rate charts!

slowr1der
March 11, 2012, 04:34 PM
I'm thinking it may just be the powder. The reason I say this is a buddy was shooting some factory Federal loads out of his gun yesterday, and those cases looked almost identical, where as the Winchester loads were a lot cleaner. I haven't shot mine with factory ammo in a while, so I can't remember exactly what they looked like. It does shoot really accurately though which is why I hate to change it.

Fat_46
March 11, 2012, 07:56 PM
Before blaming e powder examine the brass. How many times has it been reloaded? Sizing multiple times can harden the brass to the point where it is incapable of expanding to seal the chamber. I've experienced it on a few wildcat cases as well as some 260 I formed from 308. Try annealing a dozen or so then load them up and shoot them. If the blackening continues it may be the load. If it abates en you've found the culprit. I anneal in a dark room, using a cookie sheet filled with water. As soon as I see a hint of red I tip the cases into the water.

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