Carbon on necks and shoulder

[muleman69]

A friend called me today and had a question on carbon on shoulders and neck. He has been resizing with expander ball in die and getting carbon on the necks of his brass. Then he removes expander from die for concentricity reasons and now the brass is coming out with not only carbon on the necks but down the shoulder . He swears his bump is only .002 . What would do this?

 

[Dusty Stevens]

Too much neck tension from not plowing the expander back thru. Carbon is making it out before the necks seal off

 

[JFrank]

Use a Mandrel (Or ) get a bushing type Die like a Wilson that utilizes a decapper rod and bushing

 

[muleman69]

Too much neck tension from not plowing the expander back thru. Carbon is making it out before the necks seal off

I believe he said it was a bushing die sizing .002 tension?

 

[cw308]

Are you shooting a light load , light loads could cause this do to the case isn't expanding to the max .

 

[muleman69]

Are you shooting a light load , light loads could cause this do to the case isn't expanding to the max .

I will have to ask him ,I believe they are a bit on the light side. But what I don't understand is that they did not do this until he removed the ball? Same loads before and after

 

[JohnKielly]

One of the byproducts of using an expander ball can on occasion be that the shoulder is pulled forward a tad as the ball exits.

Maybe if he doesn't push the shoulder back quite as much....

 

[muleman69]

One of the byproducts of using an expander ball can on occasion be that the shoulder is pulled forward a tad as the ball exits.

Maybe if he doesn't push the shoulder back quite as much....

He claims to only be pushing shoulder by .002 and it is still smoking the neck and shoulder area?

 

[Ken]

heck, I just clean it off and load it again

 

[gunsandgunsmithing]

Add powder

 

[Zero333]

I use a O-ring on the decapping stem between the die and stems lock nut. Thus the stem/expander float a bit.
Concentric is exactly the same as with out the expander.

 

[dkhunt14]

Besides light loads, too hard of brass can cause it. Matt

 

[nmkid]

My 6-284 smokes the cases also. I found a light load, (3300 fps) that shoots just great. I'll live with the dirty cases!

 

[Acsr]

Carbon in the die?

 

[KenOath]

I’ve found with my BR after several firings on cases that the carbon slowly makes its way down onto the shoulder( I assumed it was brass gardening) and also if I use a very light < .001” neck tension.. I don’t anneal and have found no ill effects in accuracy,just a little more carbon to clean out of the chamber.

 

[muleman69]

Need more info.

Is this a bolt gun or AR?
Caliber? Velocity of bullet?
Type of rifle, hunting, benchrest, etc...?

Off hand, .002 of neck tension is a lot, unless he's using a semi rifle. The best use for an expander ball is in the box that it came in, just in case he decides to re-sell the die.

Joe

Bolt rifle,.338 lapua,hunting and long range. It is a Christian arms

 

[muleman69]

I’ve found with my BR after several firings on cases that the carbon slowly makes its way down onto the shoulder( I assumed it was brass gardening) and also if I use a very light < .001” neck tension.. I don’t anneal and have found no ill effects in accuracy,just a little more carbon to clean out of the chamber.

What effect does light tension have on the rounds? Just asking

 

[Ledd Slinger]

Whidden sells a nice set of incremental expander balls that work great in conjunction with their bushing FL sizer.

https://www.whiddengunworks.com/product/expander-ball-kits-and-sets/

I decide on the amount of neck tension I want and use a bushing that sizes the neck .002" more. Then pull the appropriate expander ball through the neck that gives me the desired neck tension.

 

[KenOath]

What effect does light tension have on the rounds? Just asking

I’ve found lighter neck tension shot better and more consistent for me on unturned, non annealled 6BR brass. I tried more neck tension on BRA and straight BR and for me both shot smaller with a light neck tension. eg Loaded round .269” and used a .268” bush.

 

[muleman69]

I’ve found lighter neck tension shot better and more consistent for me on unturned, non annealled 6BR brass. I tried more neck tension on BRA and straight BR and for me both shot smaller with a light neck tension. eg Loaded round .269” and used a .268” bush.

I will try that as I need to get the BR fired up soon, been shooting gongs this winter and have not touched it.