Burn/Charred Discharge Residue On Outside of Spent Cases?

[jtduncan]

I'm using TiteGroup in 9 and 45 inside of my spent cases always seem to have discharge burns or charring on the outside of the cases when I pick them up from the ground at the range. Using Federal primers and Titegroup.

Any ideas for why it would be leaving anything on the outside of the cases?

The burn residue wipes or comes right off when you rub them a little but I don't see anybody else's cases ending up with burn marks like someone held a light to the case for a couple of minutes.

Using right in the middle of the safe range on the powder and factory crimp with Lee die at half a turn.

Ideas?




------------------
The Seattle SharpShooter

 

[Bud Helms]

JT,

'Can't remember Titegroup. Is that a slow burner? That's usually a sign of a slow burning powder.

In some of my rifle loads I routinely get soot on the outside of my brass. I just live with it, because they are consistent and accurate.

Have you been getting any smokestack ejection problems? Has your pistol been extra dirty after a shooting session? Is the soot generally distributed around the outside of the case or is it a local burn pattern that you can see repeated on all the cases?

Is your chamber wall smooth and polished or rough?

Also, are your loaded rounds chambering correctly, i.e., is head spacing correct?

Lastly, are you taper crimping? Lead or jacketed bullets?

[This message has been edited by sensop (edited January 22, 2000).]

 

[Mal H]

jt - That is usually a sign that the casing did not seal completely to the chamber walls. Most often, this is caused by low pressure or light rounds. I see it all the time with my .45 Colt which I load on the light side.

If it doesn't bother you, and it sounds like it doesn't, just clean the casings as usual. If you want to see if it is simply a pressure problem, load a few rounds a little hotter - not going over the maximums, of course. The soot should go away. If it doesn't, then there could be a problem with your chamber being out of round. That is very rare, but not unheard of. Since you don't mention that the cases are difficult to extract, I don't suspect a chamber problem. I think this is one of those "fahgiddaboutit" things.

 

[Cheapo]

Not a malfunction at all if you're talking about only two to three millimeters back from the case mouth.

It's often just a timing thing. Some gas will blow past the bullet as the case is expanding to release the slug. Just before the case mouth slams shut into the chamber wall, a tiny bit of gas gets back there.

No harm, no foul. Just happens.

 

[Bud Helms]

JT,

I think these guys are probably right.

That's the reason I was wondering about the Titegroup burn rate. I seem to recall a thread here recently where quite a few reloaders were using it in auto pistols and were happy with it.

During the firing cycle the pressure will shove the case mouth wall out and temporarily seal against the chamber wall.

Slower powders might allow some soot to escape backwards around the case walls prior to a good temporary gas seal.

If that's what is happening, I agree ... don't worry about it.

------------------
Sensop

"Put the spirit at center and the body will find it." - Shino Takazawa, sinsei, hachi dan, Keishinkan do.
(Get your mind right and the body will follow.)
Sensop's Corner

[This message has been edited by sensop (edited January 23, 2000).]

 

[Walt Welch]

Agree with above advice.

One possibility which might (although unlikely) be a cause of your problems is that the expanding plug is too large and causing insufficient friction between the case and the bullet. This is the other major factor affecting bullet pull. Easy to check, just try and push a bullet down into a resized, then expanded and belled case. If the bullet slips into the case easily, the case has been expanded too much.

I see smoke on the side of my .45 ACP cases all the time, but the loads only generate 8,000 lup. Walt

 

[jtduncan]

Well, I've bumped up some test loads 1 and 2/10s a grain to see if that will solve the problem and maybe even better accuracy.

I also adjusted for a tighter crimp to see if I could help get the pressure up even if only marginally.

Otherwise I may be looking at W231!

Thanks folks.

------------------
The Seattle SharpShooter

 

[Cheapo]

WW 231 is a GREAT powder for .45 ACP & 9mmP.

I've had nothing but good experiences with it in those calibers. (It's not for "making major" with 180-gr bullets in .40 S&W!)

Enjoy!

 

[LongDuck]

Something else to think about is that many firearms these days are designed around maximum reliability at the expense of a 'Match' chamber for accuracy. This means that the chamber is cut a bit wider to accept slight deviations in case size, thus increasing the reliability of chambering of round in a semi-auto. Definitely worth the trade off, if you ask me.

I have a Marlin Camp 9 rifle that fires 9mm reloads and routinely makes the brass hard to find, it's so black from combustion. I found that a reduced load increased the sooting, while high-power loads decreased sooting, but increased recoil and wasted powder, IMO. I just backed off to maximum accuracy and figure if I lose a few, so what? I have plenty of 9mm brass and the rifle tends to get the crappy stuff, anyway.

A wide chamber can result in the soot that you've described, but my suggestion would be to increase your crimp slightly (within reason) to increase pressures if you're in the middle of the range for powder charge, and perhaps consider switching powder to a faster type if it concerns you. I find that my sooted brass is accompanied by a sooted gun when I go to clean, so choosing a different powder would top my list behind adding crimp. HTH,