What is causing this dent below the shoulder on my Ackley Improved cases?

[Just a hunter]

This is my first Ackley. It's a 6mm AI. I thought I was bumping the shoulder too far but with my Hornady comparator I am bumping .001-.002". Thought I was using too much lube but I tried it with the least amount of imperial wax I could get on the case. It's not the same on each case which still leads me to believe it is too much lube. I've looking in the sizing die and don't see anything. I even wiped it clean and tried. What am I missing? Are the Ackley cases that finicky or am I just simply panicking because I am trying to get everything done before season opens Saturday?? Thank you in advance.

 

[Jud96]

Too much lube. I can see the lube built up on the case neck and around the case mouth. I only lube about 3/4 of the case body and don't lube the neck or shoulder and haven't had this happen since doing that.

 

[Just a hunter]

Thank you! I hope it's that simple. I think even though I reduced the amount I was putting on the case there was still too much in the die. I'm going to clean the die out again and try a few more. They're not destroyed are they?

 

[Wedgy]

Not destroyed at all, it will iron out when you shoot it.

 

[Just a hunter]

It's weird, I cleaned everything good and tried a few more and there feels like a tiny little divot but it's hard to feel and see. Should I back my sizing die out a little bit and see if a case will still chamber? If it does and the divot is gone, do I just not even worry about bumping the shoulder at all?

 

[stonehands1]

Clean your sizing inside with some gun scrubber or brake clean.
Also make sure the air relief hole in your die is clean so the air can get out as the case goes in.

 

[Eric H]

Always wipe down after sizing with lube.

 

[Just a hunter]

I'll give those things a try.

 

[Just a hunter]

I'd love to find some kind of 6mm brass other than Hornady. Also, I have the Redding Ackley dies and I don't think it has a relief hole for pressure from excess lube. I'll look and see if I can find a different manufacturer for dies and I've been looking for brass and had zero luck.

 

[Hugnot]

Most likely trapped air. Brass is soft being annealed at that area& thin at just below shoulder. Upon pushing the Ackley improved brass case having almost no taper into the die, air is trapped (many psi) between shoulder & side of the brass causing a dent. Case lube also prevents air from escaping.

The fixes are using a die with a vent hole or using the minimum amount of lube near the bottom of the case and extending the sizing time to about 1 minute per case to allow air to escape.

Attached is a pic of a Foster F/L having vent hole.

 

[Just a hunter]

I was thinking lube but air never even occurred to me. I'll have to reach out to someone and see if they can make me a set for the 6AI. I can't find anyone who advertises them except Redding.

 

[hicountry1]

Redding dies ?

No air holes in them. Did the same with my Redding 6.5prc dies.

Bought a set of hornady dies, no more dents.

 

[338 dude]

Thank you! I hope it's that simple. I think even though I reduced the amount I was putting on the case there was still too much in the die. I'm going to clean the die out again and try a few more. They're not destroyed are they?

Not at all!

 

[stonehands1]

I also have a 6mmAI. One pf my favorite cartridges. RCC makes very good brass but will cost you $6 a copy. Winchester is great brass with a little prep work. Check your local sportsmans warehouse. I seen Winchester 6mm rem ammo there the other day for $1.50 a squeeze. First box I've seen for sale in over 2 years.
I also have a couple sweet loads worked up. PM me for info if you want.