Sooting on neck/shoulder

[Behringer]

Hello everyone. Long time reader, first time poster. I'm wondering if someone can help me stop chasing my tail and figure out why I'm getting excessive sooting on neck and shoulder. Or tell me it's okay.

Im trying to get my ES in check and am wondering If this has something to do with it. Sooting is the same from 63.0- 67.5gn of powder. Necks have been turned and annealed, .005 of neck clearance. I have also noticed that if I try to put a projectile in a fired piece of brass, some are tight and some are loose. Upon further investigation I find that some necks are oval or haven't expanded fully being fired. Any insight would be greatly appreciated! Thank you

7mm rem mag.
Berger 195gn eol
H1000
Federal no. 215
Nosler brass

 

[Alex Wheeler]

A little soot on the neck and shoulder is not a problem

 

[Ralph Littlefield]

A sooty case is often a sign of a under pressure load, but I don't see enough soot here to indicate that.

I don't see anything to worry about.

 

[Behringer]

Thank you for the quick replies. Anyone have an idea why the neck would come out oval and not fully expand? Fully expanded OD neck measures .3155, not uncommon for me to see .314. Measured with a micrometer.

 

[gunsandgunsmithing]

Like others have said, I don't see a problem but more pressure will create a better and faster seal.

 

[fkimble@charter.net]

Make sure the oval neck is not a result of the case neck wacking the inside of the action on ejection.. Place your finger on the side of the case as soon as you can get your finger to it as you pull the bole back and keep lots of pressure on it so it doesn't hit on it's way out. Now check the neck.

Frank

 

[Straightshooter1]

Hello everyone. Long time reader, first time poster. I'm wondering if someone can help me stop chasing my tail and figure out why I'm getting excessive sooting on neck and shoulder. Or tell me it's okay.

Im trying to get my ES in check and am wondering If this has something to do with it. Sooting is the same from 63.0- 67.5gn of powder. Necks have been turned and annealed, .005 of neck clearance. I have also noticed that if I try to put a projectile in a fired piece of brass, some are tight and some are loose. Upon further investigation I find that some necks are oval or haven't expanded fully being fired. Any insight would be greatly appreciated! Thank you

7mm rem mag.
Berger 195gn eol
H1000
Federal no. 215
Nosler brass

Any time one is using some distance of jump, the blowby will always leave some deposit on the neck and sometimes also on the shoulder before the neck seals the chamber, like you see on your cases. Your cases look very normal to me.

 

[Behringer]

Make sure the oval neck is not a result of the case neck wacking the inside of the action on ejection.. Place your finger on the side of the case as soon as you can get your finger to it as you pull the bole back and keep lots of pressure on it so it doesn't hit on it's way out. Now check the neck.

Frank

Thanks alot. I'll be sure to check that.

 

[ScottVA]

It may be the angle of the picture, but it looks like you could have turned your necks a little further down toward the shoulder and a little into it which may have changed the soot characteristic. Or not.

 

[Dusty Stevens]

It also sounds like you either need to try a different neck turn procedure (measure a bunch to make sure theyre coming out exactly the same to the .0001 with a tubing mic or anneal your cases. Find out why the seating pressure is varying

 

[gunsandgunsmithing]

It may be the angle of the picture, but it looks like you could have turned your necks a little further down toward the shoulder and a little into it which may have changed the soot characteristic. Or not.

It also sounds like you either need to try a different neck turn procedure (measure a bunch to make sure theyre coming out exactly the same to the .0001 with a tubing mic or anneal your cases. Find out why the seating pressure is varying

Both good points! Double check your neck clearance. You should be making enough pressure to fully expand the necks, I would think. So they should all slide easily into the fired case. Like Dusty said...get em all the same but making sure you actually have the clearance you posted is way more critical and may be a safety concern if not what you think. Just double check that to be on the safe side due to some bullets not sliding into a fired case freely.

As for turning a little further down the neck, Scott might be right and that could cause issues, especially on shorter necks like a 7 Mag and even more so if the resistance you mention is at the neck shoulder junction.

This stuff may seem simple to you, I don't know, but something does seem to be wrong, somewhere, based on what you've said. It won't hurt to double check a couple of things before going forward. .005 should be wayyy plenty of clearance and I would certainly think the bullets would fall into a fired and unsized case, with that amount of clearance. But I've seen some pretty crazy lot to lot changes in powder too.

 

[mikecr]

I've seen far worse sooting.
Causes:
-Excess chamber end clearance (over trimming)
-Excess neck clearance
-Low peak pressure load
None good for low ES/SD

 

[marine52]

The thread below addresses this topic. Read all of Tim Singleton‘s posts

Interpreting carbon deposits on case necks to help determine neck thickness

Tony Boyer's book, The Book of Rifle Accuracy(which I read to learn from), page 149, describes how to read various shapes/forms of carbon deposits on the necks of 3-5 times fired cases to help determine if the case neck is too thick. On page 149, figure "1" shows a carbon ring all around the...

forum.accurateshooter.com

also Jack Neary discuses this soot on the neck at about the 12:30 min mark :

 

[Dave M.]

Hello everyone. Long time reader, first time poster. I'm wondering if someone can help me stop chasing my tail and figure out why I'm getting excessive sooting on neck and shoulder. Or tell me it's okay.

Im trying to get my ES in check and am wondering If this has something to do with it. Sooting is the same from 63.0- 67.5gn of powder. Necks have been turned and annealed, .005 of neck clearance. I have also noticed that if I try to put a projectile in a fired piece of brass, some are tight and some are loose. Upon further investigation I find that some necks are oval or haven't expanded fully being fired. Any insight would be greatly appreciated! Thank you

7mm rem mag.
Berger 195gn eol
H1000
Federal no. 215
Nosler brass

Honestly, I don’t see any issue with there being too much soot on the necks. They look fine to me.