Why are these Flat Spots on my Shoulders

[hoz53]

Loading up some Pete 6BR brass today I got flat spots on the shoulders. these are different than lube dents I have had. they are kind of a facet. i thought i figured it out by varying the amount of lube-imperial- but that turned out not to work. thing is when i size lapua with this same die i dont get the dents. die is redding S die. i cleaned the die out to but that didnt help either. not sure the round count on these but its quite a few. only been a couple firings since i annealed. what causes these flat spots??

 

[snert]

following

 

[ELR LVR]

case lube built up in the sizing die.
no biggee, it'll form out
just clean the inside of your die
----------------------------------------
Edit: also you don't have to lube the necks, because they're straight
Thats why it's building up, the lube is getting pressed down the neck and building up in the shoulder area

 

[hoz53]

case lube built up in the sizing die.
no biggee, it'll form out
just clean the inside of your die
----------------------------------------
Edit: also you don't have to lube the necks, becauser they're straight
Thats why it's building up, the lube is getting pressed down the neck and bulding up in the shoulder area

i did clean the die. even to the point i got a 50 bronze brush in battery drill. still does it. hard to believe i didnt get whatever was in there. and why doesnt it do it on lapua.

 

[ELR LVR]

i did clean the die. even to the point i got a 50 bronze brush in battery drill. still does it. hard to believe i didnt get whatever was in there.

Gotcha,
thats the only thing I have seen make flat spots on the shoulder is the die... when I get lube on the necks.
I use a q tip and some Naptha(Coleman Fuel) to clean the inside shoulder area when it does that
a brush may just spread it
Naptha is a good solvent for wax

 

[hoz53]

Gotcha,
thats the only thing I have seen make flat spots on the shoulder is the die... when I get lube on the necks.
I use a q tip and some Naptha(Coleman Fuel) to clean the inside shoulder area when it does that
a brush may just spread it
Naptha is a good solvent for wax

lube makes sense. dont have naptha but will try some other stuff. besides the brush i did use a couple bore mops. thanks

 

[tommeboy]

spray it out with brake cleaner then blow it with compressed air.

 

[6.5 forever]

Debry in your chamber or die.

 

[Hal]

Hoz

Does your die have a hole drilled into to it, 90* to the chamber ?
It might be plugged. Take a paper clip and clean it out.
Sometimes it’s hidden under the lock ring that’s used to adjust the die height.

Hal

 

[gunsandgunsmithing]

Too much lube is my guess

 

[Kracken McGraw]

I’ve gotten to we’re I just dip the neck in dry moly lube media, then wipe off the outside and then just use Hornady tin wax on the body. Seems to avoid any dents by not ever putting wax on the neck.

 

[Fire Dog]

From personal experience that looks exactly like some case shoulder dents that I had on some 6BR brass and it was a particle of un-burnt powder compressed and stuck to the chamber.
You notice that the dent has soft outline, indicating that the thing that caused the dent is not hard like a piece of brass or grit but under high compression when the case is fired solid enough to imprint the brass of the neck.
I would have a look with a bore scope but even without a look, get an AR chamber brush and give the chamber a real good scrub and see if that fixes it.
I did not notice the dents while shooting but only after the brass was cleaned and only as I was sizing and wiping the lube off the case did I see it...

 

[hoz53]

I’ve gotten to we’re I just dip the neck in dry moly lube media, then wipe off the outside and then just use Hornady tin wax on the body. Seems to avoid any dents by not ever putting wax on the neck.

ive got some of the black stuff by imperial i think. i have used it and will try it again. thanks

 

[boltfluter]

In my experience you don't need to lube the shoulder for normal sizing. I roll mine on an old RCBS lube pad. Maybe hit the neck with the crazy cloth to remove the carbon, and done. Hit that die with some brake cleaner. Go slow on the first few cases as it will be squeaky clean. Good luck.
Paul

 

[wkdickinson]

Lube on the shoulder. I dunk the necks in Imperial Neck Lube, then with just my fingers use Imperial Sizing Wax on the body of the case only (VERY little). Then size them and mandrel them. No shoulder dents anymore.

 

[SeabeeKen]

Loading up some Pete 6BR brass today I got flat spots on the shoulders. these are different than lube dents I have had. they are kind of a facet. i thought i figured it out by varying the amount of lube-imperial- but that turned out not to work. thing is when i size lapua with this same die i dont get the dents. die is redding S die. i cleaned the die out to but that didnt help either. not sure the round count on these but its quite a few. only been a couple firings since i annealed. what causes these flat spots??

My first thought would be to clean the die. However, I have had Redding dies do this with very tight formed brass because there was no vent hole and the case and wax seal so tightly it dents the shoulder. This was the reason I stopped using Imperial and went to Royal which solved my problem. Haven't had a dented case since. If your die has a vent like Hal mentioned then it is likely plugged.

 

[clowdis]

Since it appears to go all the way around the case shoulder I'd say you have some chatter from the chambering reamer. How old is the chamber?

 

[Kracken McGraw]

Since it appears to go all the way around the case shoulder I'd say you have some chatter from the chambering reamer. How old is the chamber?

I’m with you and Firedog now. Too much lube usually doesn’t make dents all the way around like that.

 

[CJ6]

Is this NEW brass (unfired) that you're prepping??
If it is I'm wondering if the case body might be a touch long and the die is trying to force the shoulder back and it's starting to collapse.

 

[RED DIRT]

Loading up some Pete 6BR brass today I got flat spots on the shoulders. these are different than lube dents I have had. they are kind of a facet. i thought i figured it out by varying the amount of lube-imperial- but that turned out not to work. thing is when i size lapua with this same die i dont get the dents. die is redding S die. i cleaned the die out to but that didnt help either. not sure the round count on these but its quite a few. only been a couple firings since i annealed. what causes these flat spots??

@hoz53
looks like oil dents from the die not bleeding off the trapped air inside, to me. Clean out the tiny little air bleed hole in your sizing die. Take a tiny flashlight, hold it up to the entrance of the die, you should be able to see the light shinning inside the die when looking through the air bleed off hole of the die. Use less lube.

Go slow when resizing, so that it gives the die time to push out the air that`s trapped up inside as the case is being sized. You`d be surprised at how slow that air come out of the bleed hole, even going at a regular pace of sizing even if you used a dry lube technic. Wet lubing increases problems when going "to fast" during sizing.

I use the Hornady case spray lube. I`ve never had an issue with the Hornady case spray lube.