What causes excessive soot on a carriage body?

[CamTheBam]

Hi Guys,

As the thread title suggests, I'm keen to learn what causes excessive soot on a cartridge body.

In particular, N565 in 6.5PRC under a 140gn ELD-M.

Normally I'd use RL26 which doesn't cause this problem, but is getting tricky to find.

Would neck-turning cause this problem?

 

[Dan-Schenk]

What speed are you getting? Because it sounds like the case neck isn’t expanding to seal. You might just need more powder, but that depends on where you are in the charge.

 

[CamTheBam]

53.6gn of N568, which is Vhit's max load for the cartridge.

I'm seeing about 2,680fps, which I thought was poor.

I'm used to getting 3,050fps with RL26.

 

[Gabe22BR]

Would neck-turning cause this problem?

In a factory chamber ???
Depending on how much you took off…

Yes
It’s not sealing up, ( expanding)-your losing velocity..

 

[CamTheBam]

I'm currently at 13 thou neck wall thickness

 

[fkimble@charter.net]

What is the chamber neck size?

Frank

 

[CamTheBam]

What is the camber neck size?

Frank

How would I determine that?

 

[quest450]

measure neck OD of a fired case and add a thou, that should get you pretty close

 

[SeabeeKen]

53.6gn of N568, which is Vhit's max load for the cartridge.

I'm seeing about 2,680fps, which I thought was poor.

I'm used to getting 3,050fps with RL26.

Looking at your load, grt shows you are only producing 43,000 psi. pmax allowable is 63,800 so you may need to up the load to be sure the case seals.

 

[J_idaho]

In particular, N565 in 6.5PRC under a 140gn ELD-M.

53.6gn of N568, which is Vhit's max load

Which powder are you using?

 

[LCazador]

That sounds like N565 is too slow burning for your load. Try N560 or H1000 if you can't find RL26.

 

[FeMan]

I often get powder residue back into the shoulder of the 6.5 PRC cases, but not the body. I anneal each firing and use the absolute minimum shoulder setback - no more than 0.001" under what I need for a clean bolt close. This minimizes the soot on the shoulder but doesn't eliminate it. If I bump the shoulders just 1 thousandth more, the soot gets bad.

The necks on mine obviously aren't sealing. I think it is because the Lapua 6.5 PRC cases are stoutly built. The neck/shoulder junction is particularly strong and that consequently that big shoulder is slow to expand. I reload for dozens of cartridges and don't have the issue with anything other than the 6.5 PRC. I tried Hornady brass and didn't have the issue, so I think it is the brass in my case.

 

[Ed kof]

I just had this problem with a 6creed. A proven load. I ran out of reming benchrest primers and used br4 instead. Problem went away when I got some more Remingtons. Edk

 

[old codger]

How many times have the cases been loaded? Do you anneal the cases? I is possible that the case necks have work hardened and are not expanding enough to seal.

 

[6MMsteve]

Make sure your chamber is clean Alcohol or lighter fluid, cases are clean alcohol or Acetone, before you fire anything,

 

[10XSHOOTER]

Are you using a suppressor? this can cause soot on case.

 

[orkan]

Hi Guys,

As the thread title suggests, I'm keen to learn what causes excessive soot on a cartridge body.

In particular, N565 in 6.5PRC under a 140gn ELD-M.

Normally I'd use RL26 which doesn't cause this problem, but is getting tricky to find.

Would neck-turning cause this problem?

 

[Mike TackleBerry]

Are you using N565 or N568? N565 is a good powder for 140s while N568 is slower burning.

 

[CJ6]

Do you anneal? If not try it.

 

[Mike TackleBerry]

Yes neck turning can cause that especially if you neck turned the brass and the chamber wasn't designed for it.