Bumping the shoulder

[Jaeger]

Hi, since I only have the one rifle in it,  I've been neck sizing my 338 Fed brass and my buddy tells me I am "bumping the shoulder".

 

I've asked him what he means by that but he is not articulate enough to tell me exactly what "bump the shoulder" means or, more importantly, how to determine if it  has happened.  Nor can he tell me what benefits or loss it provides.

 

I figure it means setting the shoulder back a little while neck sizing but figured I'd ask the experts here.  So here we go.

 

What is bumping the shoulder, how is the die adjusted to do or not do it and again, more importantly, how can I see or measure it so I can tell whether its happening or not?

 

Thanks in advance guys,

 

Jaeger

Edited October 22, 2015 by Jaeger

[shawnhu]

You generally need to bump the shoulder of a case when you can no longer get the case to chamber without forcing the bolt to close. This is usually an indication of high pressures as well.

To set the minimal amount of shoulder bump, you'll need to purposely expand a case where it needs to be bumped and keep bumping it and chambering it until you get it to fit at small increments.

Hope this helps.

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[Lawdwaz]

I'm reluctant to hang this link as the language and wording are rough and it doesn't really delve into "bumping" a shoulder but trust me, you'll only bump the shoulder a smidge if you follow from the start all directions.  The gist of it "is starting at the star">

 

Throw away your neck die and start (and stay) with a FL die.

 

Trust me on this one..............

 

 

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