What is causing this burr on my case mouths? Redding type S die.

[Tim K]

Rem .260, Lapua brass. Redding type S die with 0.293" bushing. The expander ball is being used.

I get this very prominent burr on the mouth of every case. It's so big it won't chamber or even go in my Giraud unless I remove it first. It's completely taking all the fun out of using my new Giraud trimmer.

The burr is on both the outside and inside.

I've had the die back to Redding, and they said they can't find a problem. What in the world am I doing wrong?

http://i27.photobucket.com/albums/c173/tkulin/Brassrolledmouth2_zpsfce53b8a.png (http://s27.photobucket.com/user/tkulin/media/Brassrolledmouth2_zpsfce53b8a.png.html)

http://i27.photobucket.com/albums/c173/tkulin/Brassrolledmouth_zpsf8d90039.png (http://s27.photobucket.com/user/tkulin/media/Brassrolledmouth_zpsf8d90039.png.html)

[thvigil11]

If its rolling the brass inside and out, that would suggest something impacting straight down on the lip.... Strange. What are the case dimensions (specifically length) before resizing? After?

[Hoser]

TiN coated bushing?

Remove the expander ball and try again. If it is still doing it, remove the bushing and start again.

Try adjusting the depth of the bushing.

[Tim K]

Don't know exactly, but a pile of fired cases all measure about 2.030". Another pile of sized cases measure 2.035" I don't have before and after dims on one particular case.

Interesting observation on the top impact. I've always thought the expander ball and the bushing needed more lead-in.

[Tim K]

Bushing not coated. Removing the ball was my first thought. I'll give it a try next time I size.

[thvigil11]

Doesn't sound like long cases. I agree with Hoser on pulling the expander and trying it without. Maybe mic the expander and see if its too big. Should be a little bit bigger than .260. My guess is .262-.264 (without using my google-fu)

[Duman]

[2cents]It's hopeless, you're screwed. Just to help out, I'll relieve you of all that scrap brass.

[XC700116]

Looks like the chamfer on the case mouth is contacting the bushing "stop" (for lack of a better term), Like hoser recommended back the bushing out a couple turns and see if the burr goes away.

[Tim K]

After considerable fiddling around, I think I've determined it's from spending too long in the SS pins tumbling off the lube. I sized a few cases that had just been fired, and they came out perfect. I'm going to back off on the cleaning before sizing and use corncob after sizing.

[thvigil11]

Holy Hell. Glad you found the issue, I was staring at my Redding Dies last night trying to figure out what could be causing your problem. I'm happy you figured it out. Personally, I have always stuck with just walnut or pecan media. (Used to get crushed shells for free when i lived down in Las Cruces.) If a case can't come clean from that, I usually just toss it. I'm actually very quick to pitch a casing. What's fixable I take care of, but if there is something that gives me the slightest amount of hesitation, into the recycle bucket it goes.

[Tim K]

Well, I confirmed it myself, totally by accident. Some weeks ago (before screwing up the .260 brass) I tumbled 700 pieces of .223 brass after sizing. The lube was sticky, so I let them run really long. Sure enough, the necks are all beat to hell on them, too.

I can't wait to deburr 700 pieces by hand.