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Seater die stem compatible with 69gr SMK

anschuter2013

Gold $$ Contributor
Folks,

I'm having trouble seating Sierra 69gr. SMK's in 223. The bullet is being dented pretty badly. Please let me know what seater die and stem (standard or VLD) you've had success with seating 69gr. SMK's.

A few pieces of important information:
The brass neck ID is .222", and has a healthy 30° chamfer. The brass is clean with no carbon. I've also tried Redding graphite neck lube and Hornady One Shot. Neither helped with the denting. I tried lapping the seater stem using clover compound on a Sierra 69gr SMK to match the seater stem to the bullet ogive profile, no love there. The seater stem "was" a standard profile before lapping, not a VLD stem.

If there's an off the shelf seater die that works, please let me know what has worked for you.
 
Folks,

I'm having trouble seating Sierra 69gr. SMK's in 223. The bullet is being dented pretty badly. Please let me know what seater die and stem (standard or VLD) you've had success with seating 69gr. SMK's.

A few pieces of important information:
The brass neck ID is .222", and has a healthy 30° chamfer. The brass is clean with no carbon. I've also tried Redding graphite neck lube and Hornady One Shot. Neither helped with the denting. I tried lapping the seater stem using clover compound on a Sierra 69gr SMK to match the seater stem to the bullet ogive profile, no love there. The seater stem "was" a standard profile before lapping, not a VLD stem.

If there's an off the shelf seater die that works, please let me know what has worked for you.
I have had the same issue in the past, but doing the things you listed cured it for me, e.g. chamfer, neck lube, and lapping the stem. My seater die is a Hornady Custom Grade New Dimension.

You did not say what seater die you are using or what powder charge. Are you compressing powder?
 
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The 69 SMK isn't really considered to be a VLD, so it shouldn't require a VLD stem. A tangent ogive stem should work fine.

If the brass is chamfered and at a 0.222" diameter, this is not a common cause issue. Even work hardened brass at that diameter shouldn't cause seater marks on the bullet.

By chance, are we discussing a compression load?
Does an empty case also dent a bullet?

Have you tried passing a 0.2215" mandrel all the way past the shoulder junction?

Was the neck ultra cleaned or brushed?
 
I have had the same issue in the past, but doing the things you listed cured it for me, e.g. chamfer, neck lube, and lapping the stem. My seater die is a Hornady Custom Grade New Dimension.

You did not say what seater die you are using or what powder charge. Are you compressing powder?
I'm using a Redding Competition Micrometer die (sliding sleeve type). I'm using various powders consisting of H4895, CFE223 and Shooters World Match. None are compressed loads.

It appears that the seater stem ogive geometry is just not compatible.
 
I've used Dillon, Lee, RCBS, Redding, and Forster. Never had an issue with seating the 69 SMK.

What is the diameter of the bullet?

How are you measuring neck ID?
I haven't measured the bullet diameter, yet. Good suggestion!

I don't have a great way to measure ID, so I mic'd the OD and subtracted neck wall thickness. Neck thickness was measured with a proper ball mic.
 
The 69 SMK isn't really considered to be a VLD, so it shouldn't require a VLD stem. A tangent ogive stem should work fine.

If the brass is chamfered and at a 0.222" diameter, this is not a common cause issue. Even work hardened brass at that diameter shouldn't cause seater marks on the bullet.

By chance, are we discussing a compression load?
Does an empty case also dent a bullet?

Have you tried passing a 0.2215" mandrel all the way past the shoulder junction?

Was the neck ultra cleaned or brushed?
None of the loads I've used are compressed. Yes, an empty case still resulted in a dented bullet. I tried the empty case seating test while I was lapping the stem. I'm using the button expander that comes with the sizer die and it is well past the shoulder before expanding on extraction. The brass is new out of the box Norma sized with typical neck chamfer prep.

I'm at a loss because I have an RCBS seater that does a much better job, but isn't micrometer adjustable. The micrometer adjustment is a feature I want, so I bought the Redding but it's not working out so well. I think I might try the above mentioned idea of using JB to form a perfect mirror image, maximizing contact to spread the seating load over a large area instead of a small ring.
 
Here's a picture attempting to show the denting. If I were to take a guess, the dent is more than a few thou. Not only visual, but easily felt too.20231201_204647~2.jpg
 
A Hornady seater will crimp the case if setup allows it to do so. It sounds as though you're crimping and going a bit further which squeezes the bullet between crimp and stem. Try turning the die up a turn or two and see what happens - that should prevent crimping.
 
A Hornady seater will crimp the case if setup allows it to do so. It sounds as though you're crimping and going a bit further which squeezes the bullet between crimp and stem. Try turning the die up a turn or two and see what happens - that should prevent crimping.
I don't have or use a Hornady seater die or any seater die capable of crimping. I do appreciate the suggestion though, never know what the future holds.
 
I have had significant problems with the Redding Competition seater. 2 seating stems cracked and deformed enough to render the die unusable. I sent the die back to Redding for repair, twice, and upon return the second time there was a note saying I was abusing the die using heavy bullets and heavy powder charges. I only use the Redding Comp die now with light bullets, ie; 50-55 grains. Bought a Forster and never looked back. Good luck with yours.
 

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