Full length sizing issue

Hoping someone can help with this. I had a Lee Turret press that I used with Redding full length sizing die. It was working okay but I was getting abit of varioation with shoulder bump. So I have perchased Redding Boss press to try and gain a little more consistency. I am trying to set this up now. But... If I wind the die down on to the shellholder, which I assume woudl give me maximum shoulder bump, I am getting no shoulder bump at all and in fact my cases are increasing in length from 1.6340 to 1.6350.
Can anyone tell me what is going on here? If I wind the die in any further it just starts pushing the ram down.

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Originally Posted by Samburges

Hoping someone can help with this. I had a Lee Turret press that I used with Redding full length sizing die. It was working okay but I was getting abit of varioation with shoulder bump. So I have perchased Redding Boss press to try and gain a little more consistency. I am trying to set this up now. But... If I wind the die down on to the shellholder, which I assume woudl give me maximum shoulder bump, I am getting no shoulder bump at all and in fact my cases are increasing in length from 1.6340 to 1.6350.
Can anyone tell me what is going on here? If I wind the die in any further it just starts pushing the ram down.

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Looks to me as though your cases are short. First question do the cases chamber in your rifle? Some details on the cartridge, load and history of the cases would help narrow down the problem if there is one.
GPM.

The cases are Norma 7mmSAUM. New brass measures 1.6270 to shoulder. Fired brass measures 1.6340. After full length sizing with die set to shellholder they are coming out at 1.6350-1.6355.

How can I push the shoulder back if I am already down on the shellholder with the die. Ther cant beanything wrong with the die as I had no issues adjusting shoulder bump in the other press...

I must be missing something pretty simple in the setup here!!!

Sorry to answer your questions. They chamber fine . I am aiming for a length of 1.6315 when resized and this chamber nicely. Cases have been fired 3-4 times. Load is 68.1 gr 2217 with 162 eldm

Most instructions with any die set will tell you to screw down the die until it touches the shell holder + a bit more, 1/4 or 1/2 turn. That takes up all the mechanical play in the press linkages (something that setting it to touch the shell holder when there's no case there won't do) and gives you maximum sizing.

If the brass has been fired a few times, it might be hardening and it's time to have it annealed.

Sounds like you are using a Hornady comparator and measuring to a datum on the shoulder using the 0.420" insert. I have measured new 7mm SAUM cases and get a result close to yours. I work in metric so will take a little time to convert my results but I wonder first why do you want to set your shoulder back from fired so much? and if the cases sized chamber freely what is the problem? Will get back to you a little later with more.
Regards Grandpamac.

I understand why you changed from the Lee press to the Redding.
As the aluminum Lee press bends under pressure.

Don't worry about the length to shoulder increasing. As the brass will probably just have a sharper angle on the shoulder leading to the apparent increase when you measure it.
It happens with my Redding .223 F/L die too.

You should be setting a full length die to only just bump the shoulder back anyway.

Perfect. This has sorted it. Thanks for that. I thought once you hit the shellholder that was it...

Greetings again,
Fired Factory cases come out of my chamber at 1.631" And handloads at 1.6315". Sized in a Redding body die hard down on the shell holder they measure 1.621" so I suspect your die is not hard down on your shell holder yet. There is a small amount of spring in any press, mine is a Redding. Anyway if the cases chamber fine don't fix it. If they start to chamber snug you can turn the die down a little more, a tiny fraction of a full turn, to fix it or shout yourself a set of the Redding competition shell holders. Although expensive they are excellent. I have just set my die to size cases to 1.629"
Regards Grandpamac.