soot, soot, soot

[paulnyc]

I searched through the threads and didn't find much about soot. I am shooting 22-250 through a remington vtr - reloaded with H380 powder - light load - was very accurate at 100 yards - sub 1 moa. I did push the necks back a little more than before.

The spend brass had soot around the neck and rim - thick black soot -

what causes this?

thanks!

 

[desertHK]

Re: soot, soot, soot

did you trim your cases too short?

 

[Victor N TN]

Re: soot, soot, soot

How did they shoot? If the load was safe and shot good groups, I would leave it alone.

Most times when there is soot on the case necks and maybe shoulder, the loads aren't hot enough to expand the cases.

 

[BOLTRIPPER]

Re: soot, soot, soot

the black is a function of how the gun was plumbed....as in how the chamber is cut and concetricity of the brass to the chamber....my bet is the struck primers were all NOT centerpunched also.....

 

[former naval person]

Re: soot, soot, soot

My bet is that the light loads don't seal the neck/chamber interface before the powder debris gets pushed back into the chamber. Victor has it. If you are going to use really light loads, then neck size only. The brass will be pre-expanded and the seal will be by the neck only. If really light...you may be sooty anyway.JMHO

 

[81Z4ME]

Re: soot, soot, soot

My M1 Garand with Greek surplus ejects nice clean brass with somewhat flattened primers - around the edges a little. With my reloads (similar bullet, CCI#34 primer, IMR4895 - about 48 grains I think but I don't have my logbook with me, in civilian cases) the neck/shoulder is sooty and the primer looks like new except for the firing pin mark.

Its a light load, but it sure shoots good groups.

 

[MitchAlsup]

Re: soot, soot, soot

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">My bet is that the light loads don't seal the neck/chamber interface </div></div>

Completely agree. Generally, soot on necks is a sign of underpressure.