I think I saw someone ask this question a while back, but I can't remeber the answer.

I have dirty case necks on the outside of my 6.5 X 55 cases. Sometimes the "soot" is quite heavy. What does this mean? I think I remember someone saying to increase powder charge slightly and this would dissappear. What's the answer to this problem?

Thanks,

The brass case is the "gasket" that seals the breach off from the chamber.
If the chamber pressure isn't high enough, the neck won't expand completly, allowing "soot" to be deposited on the outside of the neck. Another possabilty is that the neck area, of the case, has work hardened enough that it is no longer capable of making the seal (annealing would help in this instance).

In my opinion, it just means that you have a generous amount of space between your neck and your chamber. If you can find brass with a thicker neck, you would see less of this. It just means the bullet leaves the brass before the brass presses against the chamber, letting the powder get between the case and the chamber.

Sometimes, if your pressure is low, increasing the pressure reduces dirty necks.

It's really no big deal. JMO

Although I don't believe that this indicates a problem, it does indicate that powder gases are getting around the neck. In my 7-08 it is much more prevelant when using H414. I believe that this is caused by a slow burning powder which does not reach peak pressure early enough to seal the neck before this happens. Faster powders do not exhibit this condition.
Either way, it is easy to remove the most stubborn fouling on the outside of necks with a few quick twists against 000 steel wool.
VH

I don't think it has anything to do with the space between the case neck and the chamber. I only say this because I was fireforming brass on my tight necked 7-08 Improved yesterday and was seeing 'sooty' necks. The clearance between the case neck and the chamber is a mere .0025 inches. (.308 neck, loaded rounds meaure .3055).

By 'improved' standards, these fireforming loads were pretty low pressure, so I think there is something to what 'Varmint Hunter' suggests.

Michael

Sooty case necks are mostly due to low pressure.

Low pressure means
a - case does not seal sufficiently (neck or even body=wind in your face)
b - insufficient combustion (more pressure=more heat=better combustion)

worse than sooty case necks: you need much more time to clean your gun.

[ 07-24-2002, 14:46: Message edited by: waitaminit ]

SAWBLADE,
Soot on a case neck is not a problem. If the soot is on the case shoulder or body, then there is a problem. Soot on a case body is usually coupled with dents in the case body full of soot. The cause of this is usually a reduced powder charge or a powder with a burn rate much to slow for the load.
Soot on the neck is normally caused when the neck starts to spring back after firing. The bullet may not have left the bore and cases are forced around the neck. Good luck.

Blade:

You didn't say if the firearm you use is a military surplus or something commercial. The reason I bring this up is a lot of milsurp rifles have generous throats for many reasons.

I have an M44 (7.62X54R) that had a lot of soot on the cases. Switching to a magnum primer solved that problem.

It's a cheap thing to try.

Ryan

I have somewhat "sooty" necks on new cases with next to maximum loads and a good fit in the chamber.
This contradicts allmost everything. So let's first define what a sooty neck is....
A little/Some powder burn sooting is normal.

In general, Fast powders soot less than slow.

K&B
Niels

I also have soot on the case necks of my .22 CHeetah mkII that I just had built by Shilen. I didn't think much about it until I read this post. It has a 8 twist 4 land barrel and I shoot 75 gr. A-maxes @ 3550 fps and Varget powder. It has a tight neck with .0015 clearence and builds up enough pressure to take most of the radius out of the primers (almost flat). Now it has me wondering?

Now, I have been called an idiot and stupid, nobody has yet given me a scientific/physical explantion of why. I load my 10 ga blackpowder hammer shotgun brass cartridges with 150-160 gr of FFG with a 1 oz roundball projectile. Have a Hodgdon load data for a 2 oz load of 140 gr of pyrodex, which I believe is equivalent to FFG. i think you can bump up the charge quite a bit for half the weight projectile.

I get powder staining on the brass, which I as a previous poster said, just use steel wool, cleans up real good(well
Is this indicative of anything? I use Elephant powder. There is no real difficulty in extracting the brass, don't see any of the signs that I have learned are supposed to imply over loading, lots of research seems to say that it is hard to overload a bp gun. I have backed off to the 140 gr range due to earlier comments about my sanity, they just don't know, I am insane, been for years, I just choose what I be insane about!

So, does anyone have comments about this? One poster said I should be able to go to 200 gr. The shotgun is over 100 years old, is not Damascus, and was checked out by a gunsmith. I have probably shot 50+ rounds at the level mentioned above, I still be here with all appendages, but it do hurt, which I love, shouldn't a 10 hurt? Any info is appreciated, if I already posted this here, sorry, been wandering around the forums quite a bit, and ya forget where ya been sometime.
rob the guy who been called all kinds of intelligence insulting things-they be way off base-don't let the silly grammar fool ya, I be from texas with a lota grad school hours in engineering--I was on a board where I was roundly critizied for listing my education, is that wrong? I kinda think an engineer gonna know more about engineering type things than a psychologist with alot more schoolin, course, engineers can't spell worth a damn

Sawblade,

This is a common problem with the 6.5x55. I have one, and this was a constant source of concern when I first got it. It happens with factory as well as handloads, and you can get sooting right the way down the side of the case.

What you need to remember is that this is an old design, and there are many old rifles out there. Load data is pretty moderate because of this. Also, the neck on these is really quite thick - so it will be harder for them to obturate, especially with a moderate load.

What to do? Well, you could just ignore it. If you don't want to, I did find that a change of primer helped. I was originally using CCI, and changed to Fed 210s. Almost completely eliminated the problem.

I have an article that I scanned in from a UK publication, specifically on loading the 6.5, and mention is made of sooting. If you'd like to read it then drop me a mail with details of where I should email to, and it's yours.

Good shooting

Patrick

Big_R,
The rifle is a Rem. 700 Classic.

Thanks for all the responses.