Ugly Lapua brass

[Dimner]

The scratches on those cases remind me of the brass for my 7x57 chamber that is slightly off center. I get scratches like those just at the base of my brass when resizing. After sizing about 50 cases I get a very small buildup of brass goo (lube and ultra tiny specks of brass) on my shell holder and the mouth of the die.

 

[Tesoro]

The scratches on those cases remind me of the brass for my 7x57 chamber that is slightly off center. I get scratches like those just at the base of my brass when resizing. After sizing about 50 cases I get a very small buildup of brass goo (lube and ultra tiny specks of brass) on my shell holder and the mouth of the die.

I dont understand how a crooked chamber could affect how your cases are sized in a die. Is your chamber a tad oversized so you are in essence 'small baseing' with a f/l die? do you get smear marks above the ejector groove? Thats about the only way you can get brass mixed with your lube. IMO if you are getting lube reside all over the place then you are using too much lube.

 

[Idaho-Lefty]

Tubb Version One Chamber in Criterion Barrel, Forster Dies and, beautiful, NORMA 6 xc Brass = NO,.. fudging,.. "Issues" for Me and, I Happily,.. Tell everyone that, wants to shoot, a 6 XC.
NO Fire forming or, Making Brass,.. for Me !
But, I'm NOT, a L-R,.. "Competitor" with, an expensive BR Rifle, either.
BugHoles in the 2's,.. make me, Happy !

 

[Tesoro]

Tubb Version One Chamber in Criterion Barrel, Forster Dies and, beautiful, NORMA 6 xc Brass = NO,.. fudging,.. "Issues" for Me and I Happily,.. Tell Everyone that, wants to shoot, a 6 XC
NO Fire forming or, Making Brass,. for Me !

Yeah well I am V2 fat neck long throat! I have a zillion magnum SRP's so need to use SRP brass. Peterson is fine but they are out of SRP 6xc until next fall. Cant get Magnum LRP anywhere. Thus the Lapua SRP Palma conversion hassle. But Lapua is better brass so not all lost! I am gonna shoot Prairie dogs at 1k this spring on a trip so need ammo stock!
But the brass comes out nice

 

[Tesoro]

This same exact thing happened

This same exact thing happened to me when I used a hand drill and steel wool to give brass a high polished finish.

The issue is that you are simply polishing the surface of the brass too much. The brass being spun at high speed in an abrasive pad causes the surface to become way too smooth. The surface of a sizing die also has a very smooth finish. The mating of two super smooth surfaces causes excessive friction and galling on the brass in the die when you size the case. All of those lines are brass being scraped off and left on the wall of your FL die. It will keep building up in the die and get worse the more you size the cases without cleaning the die. And unfortunately, it's not very easy to clean off the walls of a die.

If you want clean cases after every firing, just run them in a media tumbler and nothing else. I know the brass is pretty when polished really bright like that, but trust me from my own experience, that if you keep polishing the cases at high speed in a drill with 3M pads, you will continue to have this issue. A very smooth metal surface on another very smooth metal surface is not a good thing. Don't want too high of a polished finish on a chamber either.

You might have something here! Thanks. I did have some concentric rings in my chamber that were imprinting but polished out. My smith said a chip was run thru it. But what I am getting now is different. And I just looked at a pic I took of my first practice attempt at the 308>6xc forming process. 7-08 gutted f/l die>243 gutted>6xc Wilson to do the shoulder. If you look at the finished case on the right you can see one of those frigging ring groups!!!. And that case never fired or been in my chamber! I have looked inside my Wilson die with a loupe but didnt see any brass buildup, but was looking for scratches. Will get out the borescope.
I used to vibro tumble all my brass but recently switched to the 3m pad to preserve my carbon inside the neck and get the cases cleaned up faster.

 

[Dimner]

I dont understand how a crooked chamber could affect how your cases are sized in a die. Is your chamber a tad oversized so you are in essence 'small baseing' with a f/l die? do you get smear marks above the ejector groove? Thats about the only way you can get brass mixed with your lube. IMO if you are getting lube reside all over the place then you are using too much lube.

About 6 months ago, I started a thread here asking if any one could figure out the brass schmutz I was getting on the bottom of my die. The consensus from the gents (shooters and gunsmiths) I trust mentioned the likelihood of a concentricity error in the chamber. The rifle shoots great, so I am not all that concerned.

It's hard to quantify the amount of schmutz. I use the same lubing technique for all my reloading. Only this cartridge shows up with any schmutz after a long string of resizing. No other cartridge I have accumulates lube. After 50 pieces of sized brass, I get schmutz the size of a half dount sprinkle. Maybe less. Just enough to see on your finger.

Anyway, all of the above is not really relevant to your situation. The intent of my comment was that your vertical scratches remind me of the vertical scratches I get at the bottom of my cases from my less than concentric chamber.

 

[Tesoro]

Oh I get it..like the bolt face is not square to the chamber so your case was actually fire forming slightly cock assed to the case base, so when you put in die it has to re-square it to the case base. Never heard of this but if so seems like you would have seen a nice smear above the injector, like you can get with a small base?
Seems like the chamber would have to be waaay off bore center for this to happen. If so you should have noticed some excessive windage issues when sighting in, unless your barrel wound up being accidentally timed so the off center axis was vertical with the receiver. Or I am probably just suggesting nonsense!

 

[Ledd Slinger]

You might have something here! Thanks. I did have some concentric rings in my chamber that were imprinting but polished out. My smith said a chip was run thru it. But what I am getting now is different. And I just looked at a pic I took of my first practice attempt at the 308>6xc forming process. 7-08 gutted f/l die>243 gutted>6xc Wilson to do the shoulder. If you look at the finished case on the right you can see one of those frigging ring groups!!!. And that case never fired or been in my chamber! I have looked inside my Wilson die with a loupe but didnt see any brass buildup, but was looking for scratches. Will get out the borescope.View attachment 1530025
I used to vibro tumble all my brass but recently switched to the 3m pad to preserve my carbon inside the neck and get the cases cleaned up faster.

Yeah sometimes you need a scope to see the brass deposits because they are pretty thin and will be 'smeared' on the die walls. Pretty easy to see deposits on a neck bushing if you are using one because it will do the same thing to the brass. Stop polishing, maybe don't even tumble for a while and it will go away. After learning this lesson the hard way myself, I usually only do a quick cleaning of the necks and shoulders on the brass by hand with steel wool. If cases get dirty enough, i might tumble them for a short while. No issues since I quit polishing brass like that.

I've tried a lot of lubes over the years and a light coating of Imperial sizing wax on the entire body of the case is what I trust most.

 

[Tesoro]

Yeah sometimes you need a scope to see the brass deposits because they are pretty thin and will be 'smeared' on the die walls. Pretty easy to see deposits on a neck bushing if you are using one because it will do the same thing to the brass. Stop polishing, maybe don't even tumble for a while and it will go away. After learning this lesson the hard way myself, I usually only do a quick cleaning of the necks and shoulders on the brass by hand with steel wool. If cases get dirty enough, i might tumble them for a short while. No issues since I quit polishing brass like that.

I've tried a lot of lubes over the years and a light coating of Imperial sizing wax on the entire body of the case is what I trust most.

thanks!! I bore scoped my wilson die today and zero 'copper' that i could see. they are smooth as a baby ass with just micro vertical lines. Yes I only use imperial very light. But for forming I use lee case foring wax that is water based and let it dry. Magical stuff. Never get a grab on extraction with the imperial so I know i am ok but no build up. I believe you after noticing those same spirals in the pic I posted of brand new formed brass. That was a junk new case like a r/p i used to test but that makes no diff. I just loaded up 80 rounds out of those scarred cases and I'll quit the polishing, as your recommend, other than knocking off the carbon on the necks by hand twist. I have a call into wilson as I would like to see what they say and will post. But that is definitley 'it'. Will we all be on our death bed before we finally figure out all the nuances of reloading 'pre-owned' brass!! hah