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

[TimK]

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?

 

[BDA2]

Almost looks like your brass is hitting the top of the die and getting smashed.

Posted Via Glade Plug In.

 

[Milo 2.5]

In your pic, is the brass sized? Did you chamfer it before firing?

 

[Rob01]

First, take the expander ball out. You are sizing down to the proper size and then pulling a expander back through it and messing it up.

As to the problem, yeah it does look like it is going up and hitting the top. It's all the way around? Do you tighten the steam down until it hits the bushing and then back it off an 1/8 of a turn so the bushing is floating?

 

[DAVETOOLEY]

Compare new unfired brass to these. It could be from pinch trimming the brass to length during manufacturing.

 

[Milo 2.5]

First off I agree with Rob and BDA that the brass looks like it's been in a head on collision. And hope for your sake that the brass isn't too long from not being trimmed, you're gonna look like quite tool! And I don't believe it's bottoming out on your die, it wouldn't split 2 ways, inside and out. I think if it was hitting in the die it would crunch the shoulder or case-shoulder junction?

My thoughts, you bought into the fallacy that Lapua brass was load and go, in most of the time it is. But in today's crunch, a lot of shit has fell through the cracks, and that lot of brass needed some case mouth work before firing. I do agree Lapua brass is top of the line, but IMO Norma brass requires less prep, compared to Rem, Win. etc..
You just have a buildup of excess crap on the mouth, somehow you need to find a 3 way trimmer system that will clean it up, then chamfer good and the problem shouldn't come back. Trying to size that brass will result in shavings from inside and out getting all over the brass and die creating a big mess.
Also, .293 bushing seems a bit large, my 6.5 creed needs a .289 bushing, and I can't envision 260 brass being any stouter? Like Rob said, loose the expander ball, it's just negating what you were trying to accomplish. Find the black decapping pin retainer in your die box and replace the expander.

Case in point about quality control, buy a 550-1000 rd box of Rem bulk brass and compare it to a packaged bag of 50, good luck finding bulk brass today, but believe me there's a world of difference!

 

[Sixfivesavage]

First, take the expander ball out. You are sizing down to the proper size and then pulling a expander back through it and messing it up.

As to the problem, yeah it does look like it is going up and hitting the top. It's all the way around? Do you tighten the steam down until it hits the bushing and then back it off an 1/8 of a turn so the bushing is floating?

So with the Redding bushing dies you don't run an expander ball at all? Just the bushing?

 

[Milo 2.5]

So with the Redding bushing dies you don't run an expander ball at all? Just the bushing?

Yes, use the black looking expander that comes in a little bag in the die box. Use the expander only to straighten dinged case mouths, but getting expander dies for this is way handier.

 

[TimK]

It's not hitting the top. The bushing is almost twice as tall as the neck is long. Not possible. This is 4th cycle on this brass, and I trim to length every other cycle. I do indeed adjust the bushing with the 1/8 turn business.

I'll try omitting the ball on the next sizing. I don't understand how the ball could be raising a burr on both inside and outside, but I don't know what else to try.

 

[Rob01]

So with the Redding bushing dies you don't run an expander ball at all? Just the bushing?

Nope. There is another thinner black part that will hold the pin in place but is much smaller and won't touch the neck like the expander ball.

The expander ball might not be the problem for the OP but it's just something that should be known that it is effecting the neck tension you are setting with the bushing.

 

[Milo 2.5]

It's not hitting the top. The bushing is almost twice as tall as the neck is long. Not possible. This is 4th cycle on this brass, and I trim to length every other cycle. I do indeed adjust the bushing with the 1/8 turn business.

I'll try omitting the ball on the next sizing. I don't understand how the ball could be raising a burr on both inside and outside, but I don't know what else to try.

Ok, you say you're trimming, how about chamfering and deburring, maybe the Giraud isn't set right.
You're causing this somehow, but it's not the expander ball.

 

[DAVETOOLEY]

I agree it's not the expander ball. In fact in conjunction with the proper bushing many use the expander ball to manage variations in neck thickness to get uniform tension by just slightly expanding the neck a few thousandths. I've got expanders in multiple calibers that I've used over the years on my target rifles in pursuit of uniform neck tension. In your first picture it appears there is material on the inside of the neck as well. That points to your trimmer.

 

[Gray]

I have also had some to do this with Lapua 260 brass, a Redding Competition Neck die and a .293 bushing (Correct bushing with .293 unloaded/ .295 loaded/ and .297 neck in chamber). Mine has never caused a problem with feeding though, so your chamber might be a older .295 that was used with Remington brass. I don't trim/turn or do anything additional to my brass so it's never been a problem. Just letting you know that there are others out there with the same issue, which really has never been a issue at all with mine.

 

[Milo 2.5]

I have also had some to do this with Lapua 260 brass, a Redding Competition Neck die and a .293 bushing (Correct bushing with .293 unloaded/ .295 loaded/ and .297 neck in chamber). Mine has never caused a problem with feeding though, so your chamber might be a older .295 that was used with Remington brass. I don't trim/turn or do anything additional to my brass so it's never been a problem. Just letting you know that there are others out there with the same issue, which really has never been a issue at all with mine.

This can't be a cartridge specific problem, something is not getting done right!

 

[Gray]

This can't be a cartridge specific problem, something is not getting done right!

I agree, but what?

 

[TimK]

I tumble in SS pins after sizing to get the lube off. I wonder if that could be it.

I just resized a couple more, no changes except I didn't tumble. They looked perfect. I honestly never looked closely after sizing and before cleaning.

 

[Powermac]

Your cases does not look to be camfered and deburred, witch means the trimmer will leave burrs when you trim the cases.
ANd yes STM cleaning can certainly peen your case mouths and cause similar results, fill it well up with water and run it a shorter time, should help.
STill want to chamfer and deburr at least after they are cleaned.

 

[TimK]

Your cases does not look to be camfered and deburred, witch means the trimmer will leave burrs when you trim the cases.
ANd yes STM cleaning can certainly peen your case mouths and cause similar results, fill it well up with water and run it a shorter time, should help.
STill want to chamfer and deburr at least after they are cleaned.

That's kinda the point...they won't fit in my Giraud with the burrs. I'm having to deburr before the giraud trims and deburrs. I think I'll try cleaning off the lube with corncob.

 

[jlow]

I tumble in SS pins after sizing to get the lube off. I wonder if that could be it.

I just resized a couple more, no changes except I didn't tumble. They looked perfect. I honestly never looked closely after sizing and before cleaning.

This could in fact be "peening" caused by collision of cases against each other in the SS media drum. This is a well documented effect. A few things you can do to avoid this:

1) Reduce the number of cases in each run - less cases, less collision.
2) Reduce the run time - 1 hour is all that is needed.
3) Increase the amount of SS media from 5 lb to 10 lb - the pins acts as a cushion and also cleans your brass faster.

 

[Milo 2.5]

I've heard of peening from ss tumbling, if that's actually what this is, you've got to be a record holder? Holy shit!

 

[gstaylorg]

That is not what peening normally looks like. Typical peening caused by tumbling too long with SS media will have the appearance of very tiny dimples or pits around the mouth of the neck. It is actually caused by collision with other cases in the tumbler, not with the SS pins themselves. If I had to guess, I'd say your issue might be that by using the expander ball in addition to a bushing, you're squeezing the brass on both inside/outside of the neck, causing it to flow and be excessively extruded longitudinally. However, I'm not sure why this would leave a burr on the inside of the neck. It may be this combined with the extruded brass hitting the inside of the die and rolling/pushing it back.

 

[Ledzep]

I recently received 250 cases from Midway (308 range pickups) that were tumbled or cleaned some how. Anyway, they all had lips on the mouths similar to what you've got. Requires a deburring before resizing or they come out funny.