What is the cause of this?

[WeiserBucks]

I check case length at every sizing, and always trim to minimum length. I find it's generally not necessary but once in a while a long one or 20 pops up . Good practice to adopt in my opinion , helps with safety and consistency.

 

[243winxb]

Collet die http://www.larrywillis.com/index.html

Just incase its not fixed?

 

[Deleted member 46119]

BTW there is a method to get the exact maximum case length. It takes a Sinclair Chamber Length tool. The video explains it. I have them for some calibers. I can make them for others.

http://www.sinclairintl.com/reloadi...s/sinclair-chamber-length-gage-prod32925.aspx

Then take .010 off.

 

[ChrisInKY]

One word: Donut Two words: False shoulder

Though I see it on your pictures, it's not very pronounced (yet). I just know what it is that I'm looking at from personal experience. If you hit that brass one more time with your neck sizing die, and then get it sparkling clean, you will be able to stand the cases up in a nice tight row and stare down the line at the bulges just below where your bushing stops pushing.

I just lathed all my brass and didn't take any pictures (sorry). Your solution lies in full neck sizing, neck turning and annealing. If you can't do one, you're going to wind up doing more of the others. As the donut becomes more pronounced, you will experience chambering issues after you've seated your bullet.

I promise ... it's a labor of love (grin).

 

[flashhole]

Interesting thread.

I have a Ruger #1V 25-06. Most of my brass is HXB 30-06 re-form. My favorite load is the Nosler 115 Ballistic Tip over a full case of Retumbo powder. The load is slightly compressed and near max. Brass is annealed as needed and I did neck turn the batch I'm currently using. I use the K&M neck tool, inside ream, outside turn. The load shoots very accurately in my rifle.

I get sooty necks, not as bad as the OP shows in his pictures but they do get a black residue down to the shoulder. Initially I suspected low pressure and inadequate chamber fill from the slow powder.

I tried other powders with this bullet and still got sooty necks. Accuracy fell off a bit so I went back to Retumbo.

I tried a magnum primer with Retumbo and this bullet and still got sooty necks.

Reading some of the posts regarding OAL I went and measured a batch I recently trimmed. SAMMI length is 2.494", my brass measures between 2.483" and 2.485", well below the SAMMI length.

I might try trimming some to 2.480" to see if that makes a difference. This is my only rifle where I get sooty necks but I don't pay much attention to it because it's so accurate.