shoulder bump 7 Mag

[TackDriv3r]

I was not able to shoulder bump the 7mm Magnum Nosler brass with the Redding Type S Match full length resizing bushing die. I screwed it in as far as it can go till it has a little firm contact with the ram. Still at chamber shoulder size of 2.112". I also tried with a RCBS full length sizer, still the same. Both are screwed all the way down. Does this case need a body die to bump the shoulders?

 

[Barrelnut]

How many times has the brass been fired? Short 7mm brass in a long chamber can take 2~3 firings before the brass expands to full chamber length. Same thing happens to me in a 7mm.

 

[Rich Coyle]

If I had that I would take .010" off the bottom of the die.

 

[TackDriv3r]

Barrelnut: Brass is fairly new, 2nd firing.

wildcater: It's possible because I went back to the bench and started from the highermost of the die and in small increments went all the way to the contact of the shellholder and still the same, so I turned a quarter turn more and it was pretty solid contact and it did bump .002 from that position. Looks like I may either shave a little material off the top of the shell holder or get a thinner shell holder. Has anyone used those Redding Competition shellholders? Hopefully they work.

Here is a link for shims. See the 4th picture scrolling down. http://www.larrywillis.com/

 

[TackDriv3r]

Here is a link for shims. See the 4th picture scrolling down. Innovative Technologies - Reloading Equipment

Disregard the shims, its the opposite of what I am trying to accomplish. I just need a thinner shellholder, anyone know who may have those?

 

[philipbrousseau]

the competition shell holders word towards less sizing. the opposite of what you are wanting. is it a belted case?

 

[TackDriv3r]

the competition shell holders word towards less sizing. the opposite of what you are wanting. is it a belted case?

Yes it is belted.

 

[Barrelnut]

Belted magnums can have long chambers compared to modern non belted cases. I think the long chamber is part of the design to facilitate easy chambering in harsh conditions. This easy chambering is the whole point of belted cases.

That said, it may take 2~3 firings, maybe even 4 before the case shoulder is up tight against the chamber shoulder and needs to be set back. I would consider firing the cases until they are getting hard to chamber because of shoulder length and then bump them back .002. Issue is, you maybe be bumping back a shoulder that is not even to the shoulder edge of the chamber yet. This is why you are having to screw down the die so far. Later after the case lengthens, you probably won't have screw the die down near as far to bump back .002.

On reason I suspect this is because I have used Nosler brass in a 300 RUM and found the Nosler brass to be really short a the shoulder. It was shorter than SAAMI spec if I remember correctly. I use a Hornady headspace comparator to keep an eye on shoulder lengths.