Moving Shoulders on a Case

[statjunk]

***!

I was told that bumping the shoulders back was better than neck sizing only because it only moves your brass just a hair so you can chamber your rounds no matter what.

Can someone please chime in here!

I've always neck sized only. Never had a problem but folks have warned me that a problem will creep up eventually.

Thanks

Tom

 

[bigbuck]

***!

I was told that bumping the shoulders back was better than neck sizing only because it only moves your brass just a hair so you can chamber your rounds no matter what.

Can someone please chime in here!

I've always neck sized only. Never had a problem but folks have warned me that a problem will creep up eventually.

Thanks

Tom

Tom don't give up . I've just started bumping my sholder back as i was told by a competition shooter who works for hornady that "I only need to bump the sholder back .001 to .002 thou and no more than that . This will allow you to keep from over working your brass and will help to keep that fired brass the same as your chamber end result center line to the bore or squared to the bore . so far i've noticed better accuracey doing it this way .

bigBuck

 

[boomtube]

"if I'm using a FL sizing die to bump the shoulder and size the neck is that all that is happening or is it also sizing the case all the way down to the case head?"

We can't get a 'shoulder bump die'. FL, Body bump and neck dies are our only options. Sizing with an FL die to 'bump' the shoulder is indeed Full Length resizing. Neck dies are supposed to only touch the neck, but some slip up and get bored short so it is possible - rarely - that a neck die can "bump" a shoulder and that will almost certainly cause the shoulder to swell outward at the body junction. All a body bump die consists of is an FL die that has the neck bored large enough to not touch the fired neck so, yes, it will size to the case head.

No matter what you've been told about neck sizing, it's not automatically better for accuracy nor case life than FL sizing. Only experimentation with both methods will tell any of us which works better in an individual rifle, and even then the results only apply to the tested load.

No matter what you've been told about expander buttons dragging necks or shoulders forward very much, you now know it's not true, right?

 

[dwm]

We can't get a 'shoulder bump die'. FL, Body bump and neck dies are our only options.

This is intersting as I found a way to do this.

What you need for this is a Redding body die, a Redding Small Base die, and a Redding type S neck sizer die.

With these dies you can independently control the size of the base, how far the should is bumped back, and how far and to what diameter the neck is sized to.

Kind of a pain to use separate dies, but yes, all dimensions can be controlled independently.

I figured this out because my cases were not extracting when I opened the bolt. They would stick in the chamber and not want to come out. Yes, I could have turned the body die down so more of the body was sized, but I did not want to bump the shoulder back any further. The cases were sticking at the base, but the primer pockets are fine.

This is where the Small Base die comes in. The Small Base die will not bump the shoulder, it only touches the base.

So now I use the Small Base first, then the body die, and then the neck die.

I am reducing the size of the base just enough so they don't stick in the chamber after firing, not very much much at all and bumping the shoulder 0.001" on annealled brass, then sizing the neck 3/4 of the length of the neck with a bushing that is giving me 0.002 neck tension, again measured on annealled brass.

 

[statjunk]

Thanks to all for helping me better understand this. I'm going to experiment some more over the next three weeks.

Tom

 

[boomtube]

"This is intersting as I found a way to do this. What you need for this is a Redding body die, a Redding Small Base die, and a Redding type S neck sizer die."

I'm REALLY puzzled by that.

Every SB die I've seen is simply an FL die with the lower part some two-three thou smaller than is common. What does your Redding SB die not do to a shoulder or neck that a common FL die does?

 

[dwm]

I am using the die described below, but only sizing the base 0.001 to 0.0015. When this die is set to minimumly size the base, it does not contact the shoulder or neck at all, only the base. I am not overly concerned about work hardening the base.

This is just the opposite of a normal full length die which will bump the shoulder before sizing the base, if the die is only turned down in the press a minimal amount.

I am on my 12th reload of a set of Winchester cases with plenty of life left in them.

Make sense?

------------------------------

Redding Small Base Body Die 284 Winchester


Designed to full length resize the case body and bump the shoulder without disturbing the case neck. The Small Base Body Dies are for use with firearms with custom chamberings that are tighter than SAAMI Specifications. For precise control of the amount of shoulder bump, Redding Competition Shellholders are recommended. Not for use with loaded ammunition. Shellholder sold separately.

Technical Information

Material:Steel

Die Type Included:
Small Base Body Die

Notes:
Small Base Sizing dies squeeze the brass down to minimal SAAMI specifications.
This work hardens the brass more (makes it more brittle) and shortens the case life.

 

[WRG]

I'm in the same camp with "dwm" with regards to only sizing the base & neck and not touching the shoulder. Only differance being is I use your standard FL sizer dies i.e; Lee & RCBS. My experience in nearly thirty years of handloading has taught me to leave the shoulder alone after your brass has been fire formed. This practice has proven to virtualy eliminate case neck run-out provided the chamber has been cut straight. It also reduces case stretch keeping it to a minimum extending brass life ten folds. This has helped close my groups by 30% in most cases.

However, I would not advise this practice if you're one to load at or even near max recommended charges unless you were absolutely sure what your rifle has for headspace at the bolt face or firing pin plug. I should also mention I only do this with bolt action or break action rifles. Lever actions and semi-auto's, where match grade accuracy is very rarly achieved, I will bump the shoulder back .0005 - .001 as they tend to need this extra clearance.

WRG