ADG Dimpling at the shoulder after resizing 🤔

So, on my 300 PRC ADG brass after full length resizing once fired new brass I have 10% of the 100 dimpling at the shoulder. My first thought is what the heck went wrong on my part. After inspecting dies etc I can't find anything out of the ordinary and have never had it happen with any other brass.

I honestly can't figure out why it would do this. Maybe to hard ? If that's a possibility. Not having enough give when resizing on specific individual ones. 🤷🏼‍♂️
Thoughts ?
I've had this exact same problem but with normal brass. The cure for me was way less lube on case before sizing. Cured my problems and that was 5 years ago.
 
The other thing is that I avoid lining the shoulder of my brass. Lightly lube the neck and the body, but minimal lube. I use forester lube.
 
I guess I'm a little puzzled due it being so random. If there was to much sizing lube it would be a continual thing happening on everyone from the start of excessive build up. That is not the case and it's rather random
Not necessarily. Even with a good pattern of lubricating, and if you are using the pad to roll the cartridges on, what could happen is just a little more pressure, on one cartridge, while rolling could actually build a wave of lubricant in front of the cartridge, kind of like Kneading dough. That scenario could be very difficult to control without just trying to visually look at every cartridge. If you have developed a very good routine, one still has to be careful when re-lubing the pad when it will be the most wet. Still could happen at anytime with just a little more down pressure than all the other cartridges. I can not say this is the absolute problem, but certainly something to watch out for.
Best Regards
 
So, on my 300 PRC ADG brass after full length resizing once fired new brass I have 10% of the 100 dimpling at the shoulder. My first thought is what the heck went wrong on my part. After inspecting dies etc I can't find anything out of the ordinary and have never had it happen with any other brass.

I honestly can't figure out why it would do this. Maybe to hard ? If that's a possibility. Not having enough give when resizing on specific individual ones. 🤷🏼‍♂️
Thoughts ?

Too much sizing lube or a plugged vent hole in your sizing die.
100%
 
I had a fraction of a piece of corn media once make it into my sizing die. That wouldn't typically have a random impact but if you're talking about just nudging the shoulders, some can make it through with little to no shoulder contact. I agree with the others that lube is the likely cause, just one other thing to eliminate as an issue.
 
I too experienced this with ADG RUM brass.

I started wiping the neck/shoulder with a paper towel before running it up the sizer. This corrected it.
 
I have a Whidden FL sizing die with no vent hole that I had to stop using because of this. It happened on Bertram brass that was pretty hard. I bought a Redding die and have not had any issues since. Im not sure if they forgot the vent hole or if Whidden just doesn't use them but I would definitely check to make sure yours is clean. I tried several different types and very small amounts of lube and it just kept happening.
I'll have to check mine but I'm pretty sure all my Whidden sizing dies have a vent hole.
 
Like others have said, too much sizing lube/imperial wax on the shoulder/neck. I stopped using Imperial on the neck because of this, I use it on the body below the shoulder and use RCBS dry lube on the necks. Problems stopped. This first showed up when FL sizing .257 Wby (or Norma) brass. Took die apart, cleaned really well, re-set everything and now I have no problems.
 
So, on my 300 PRC ADG brass after full length resizing once fired new brass I have 10% of the 100 dimpling at the shoulder. My first thought is what the heck went wrong on my part. After inspecting dies etc I can't find anything out of the ordinary and have never had it happen with any other brass.

I honestly can't figure out why it would do this. Maybe to hard ? If that's a possibility. Not having enough give when resizing on specific individual ones. 🤷🏼‍♂️
Thoughts ?
Try backing die off a thousands, see if better
 
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