Weird marks on my case neck. Any ideas?

[Iamero]

I took my die apart and cleaned it all. This is my first time using it but bought it used off the hide a while ago. Anyways, it’s leaving these vertical swipes around about 50% of the neck on every swipe. it’s deep enough you can feel it with my fingernail.

Should I send it back to Forster or is this something I can fix? Or does it not matter at all? If it’s purely cosmetic I don’t really care either.

 

[2aBaC̶a̶]

What kind of lube are you using?

 

[Iamero]

Hornady case lube. I’ve used that with pretty much every other caliber I have and haven’t seen these marks until sizing these last night.

 

[ZY100]

Could be some carbon embedded in your die....but try this.

Lightly chamfer the outside of the necks on a few and try them. See if it stops. Sometimes if you have thin brass on the end of the neck, during sizing, tiny flakes can peel off and go between the brass and the die.

ZY

 

[louu]

Subscribing

 

[MtnCreek]

Clean the die w/ OOOO steel wool and a nonabrasive polishing compound chucked in a drill.

 

[Hawk in WY]

My Forster dies did that as well.

Forster cleaned them up and they run fine now.

I probably could have done that myself.

Seems unique to Forster for some reason.

 

[bigdaddydmd]

I have a FL sizing RCBS die that makes those exact same marks on the necks of my 6.5CM brass. I have tried to figure it out without success so I am following this to find out. It loads and shoots just fine. I have no change in MV, SD, or ES compared to previous reloads with the same components so I have been shooting it as is. I haven't been chamfering prior to sizing since I trim, deburr, and chamfer necks after sizing. I will takes MtnCreek's advice and try to clean and polish my dies.

@Iamero So far it appears to just be cosmetic since it shoots fine, but I suspect I will shorten the number of firings I will get out of this brass.

 

[FCS]

Brass has galled to the neck portion of the die. Once brass is galled to neck, you'll have to remove the galled brass from die or it'll just continue to get worse.
Gray synthetic steel wool works pretty well wrapped around dowel to remove the galled brass in neck. Otherwise send back to manufacturer to let them polish out the galled brass.

Definitely not just cosmetic, this will lead to early splits in case neck.

 

[supercorndogs]

Forrester told me polish a die with 400-600grit.

 

[bunsen27]

Would Flitz be too aggressive of a polishing compound to use?

 

[MtnCreek]

Would Flitz be too aggressive of a polishing compound to use?

I've used flitz on dies. Seemed to work well.

 

[Brux]

Your die has brass built up in the neck area from not using enough lube when sizing. Clean it out and try some different lube.

 

[bigdaddydmd]

Do you use lube on the necks? Serious question. I use the RCBS lube and pad and just roll the cases as the directions indicated. I'll lube the inside of the necks with a neck brush wiped off on the pad, but not the outside of the necks.

 

[2aBaC̶a̶]

a scotchbrite pad works if you dont have steel wool or 800 grit. Cut a slit in a wooden dowell or a pencil.

My mandrel does that on the inside sometimes. Never on the outside, i get them slick with unique.

 

[Doom]

Flitz is a polishing compound and really NOT *edited* considered abrasive. It is safe to use.

 

[fx77]

Flitz is a polishing compound and really considered abrasive. It is safe to use.

I read Flitz is 3-3.5 microns...pretty safe to use

 

[squishee]

was given several dies that did that ..
I knew it was galled brass.
I took an exacto blade and ran it perpendicular to scrape the brass out.
I have loaded thousands of rounds from them now.
Dies have a rockwell 0f 50 to over 60 c.
It would take a ton of polishing to alter them with fine sand paper or polish

 

[DCAN]

I've had a similar thing happen. I cleaned the die out then polished the inside with Flitz. Used a short rod with undersized brush on the end. Wrapped the brush with a cleaning patch saturated with Flitz. Spun it with a hand drill. The inside of the die looked like a mirror. Cleanup with brake cleaner (non-chlorinated). Problem solved and the sizing operation was easier too. I now do this to all new dies. As of yet, I can't find a problem with doing this.
You can use a slightly more aggressive compound, 600-800, but it's hard to hurt anything with Flitz.

 

[DownhillFromHere]

Brass has galled to the neck portion of the die. Once brass is galled to neck, you'll have to remove the galled brass from die or it'll just continue to get worse.
Gray synthetic steel wool works pretty well wrapped around dowel to remove the galled brass in neck. Otherwise send back to manufacturer to let them polish out the galled brass.

Definitely not just cosmetic, this will lead to early splits in case neck.

^^^^ This. The bits of brass causing the scoring are tiny. You may be able to remove the larger ones completely or partially with an Xacto blade or similar. I too used steel wool wrapped on a dowel to polish out the remainder.

After doing so - use more lube on the necks....

 

[mmlj]

I would also endorse using Flitz on a new, unused, over sized bore mop. I use a lathe for more concentric alignment. You should be able to polish out the grit causing the lines on the brass.

 

[Doom]

I read Flitz is 3-3.5 microns...pretty safe to use

I corrected my post to "not" considered to be abrasive. It is a polishing compound.

 

[Mike Casselton]

I used 400grit paper on a patch puller and spun it up with my drill.
Cleaned it right up.

Mine was caused by too little lube because I ran out. Shoulda waited.

 

[supercorndogs]

was given several dies that did that ..
I knew it was galled brass.
I took an exacto blade and ran it perpendicular to scrape the brass out.
I have loaded thousands of rounds from them now.
Dies have a rockwell 0f 50 to over 60 c.
It would take a ton of polishing to alter them with fine sand paper or polish

The end of this is pretty much the rest of what Forrester told me.