Sooty necks. Bad chamfering?

[propliner]

I was shooting some .308 loads with AA2230 and getting some nasty soot on the necks. The rifle's throat was dirty to the point that I had to clean it so it would feed better.

It wasn't a light load and I'm wondering if poor chamfering might have caused the gas to escape back there. I dont have the brass anymore but man, that load shot really well and would like to try it again.

Would an eneven ridge of brass at the mouth cause this?

 

[kawicrash]

Tag for intrest

 

[Ganderite]

Sure sounds like a low pressure load. Did you get a chony reading?

 

[Dogleg]

Sounds like a light load.

 

[kawicrash]

Do you have the load data? You say it wasn't a light load, just curious as to the specs.

 

[propliner]

I was using 37.5 grains of AA2230 behind a 168gr bullet in Federal brass. I didn't chrony it.

I'll bump up the powder charge and use some Lapua brass this time.

 

[Keithjohn]

I found lite load and wonder if annealing the neck also helped

 

[Alpheus]

Thats a light load, and AA2230 is a quick powder to be using behind a 168gr bullet

 

[propliner]

Thats a light load, and AA2230 is a quick powder to be using behind a 168gr bullet

Well, I had no pressure signs so I guess it was too light a charge. It put 4 bullets into one hole 3 times consecutively before I ran out of ammo. I have plenty of this powder left so I'll keep working at it with a couple of extra grains to start.

 

[dero338]

It could be a light load, but it could also be a slow ignition. In my case, I solved it by using magnum primers after a couple click-bang shots on a cold morning.it was in a 6.5X55.

 

[bigedp51]

If you make a workup load starting from the suggested starting load and work up you will see two things.

1. At lower pressures you will have soot on the case neck.
2. At the start load the primer will protrude from the base of the case. And when the pressure is great enough the primer will be flush with the base of the case. At the point the primer is flush normally the case neck should also seal and no longer have soot on the necks.

Put a straight edge on the primer of your cases with sooty necks, is it flush or sitting taller than the base of the case.

Example, my 30-30 cases at 38,000 cup or 42,000 psi have soot on the case necks and the primer is protruding above the base of the case. And on higher pressure cartridges the necks should seal and the primers be flush with the base of the case.

 

[propliner]

Great stuff guys, thanks.

 

[Dogleg]

Tough brass and or hard necks can also cause sooty necks. My .204 smokes the cases up badly until I crept the loads up a bit over a grain over maximum. Then it's just fine.

 

[hunter7mmRM]

Would a light load cause this as well in my 45colt mares leg?

 

[emerson]

Would a light load cause this as well in my 45colt mares leg?

Not sure about light loads, but max loads of H110 under 250gr bullet burn very dirty in mine.

 

[TheWhole9Yards]

I get soot on the neck of my .303 when I load with surplus 7.62x39 123gr pill and powder, going to up the powder charge and see what happens.

 

[Snider shooter]

The 45 colt problem is well know to cowboy shooters using low loads. Anneal the case mouths and sote goes away. A pain when you have over 500 cases. The more info given the easier it is to diagnose the problem.