Shoulder bump question.

[A14]

Is it possible to bump the shoulder without full sizing?

I have read a couple topics on here and have seen the hornady neck bushng die, but they do not have one for the .338 lapua. Will the RCBS neck bushing die work? In the disclaimer on the page it says it will not touch the shoulder.

 

[justinbaker]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: A14</div><div class="ubbcode-body">Is it possible to bump the shoulder without full sizing? </div></div>


do you mean bump the shoulder without neck sizing? then yes

but you need a bump die, i have a redding and it works great

 

[A14]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: justinbaker</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: A14</div><div class="ubbcode-body">Is it possible to bump the shoulder without full sizing? </div></div>


do you mean bump the shoulder without neck sizing? then yes

but you need a bump die, i have a redding and it works great </div></div>

No I mean without full length sizing. I am only neck sizing my brass for extended life. Hornadys new line of neck bushing dies bump the shoulder back without sizing any of the body. This is what I want.

 

[Boncrete]

Re: Shoulder bump question.

I'm sure there are others out there if you look, but off the top of my head I know Forster makes a die that will do this.

You can neck size and bump the shoulder, and if you only want to bump the shoulder, you just remove the bushing and you are ready to go.

 

[EROCO]

Re: Shoulder bump question.

To bump the shoulder back you either need a full sizing die, or full sizing die with bushing, or a body die which does not have any neck sizing.

I dont think you can bump the shoulder back any other way.

 

[tdow]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Boncrete</div><div class="ubbcode-body">I'm sure there are others out there if you look, but off the top of my head I know Forster makes a die that will do this.

You can neck size and bump the shoulder, and if you only want to bump the shoulder, you just remove the bushing and you are ready to go. </div></div>

^^^This. Forster Bushing Bump Neck Sizing Die.

 

[leadbullet]

Re: Shoulder bump question.

I have 2 Redding shoulder bump die (223, 308), they do nothing but push the shoulder down and you can even do it on loaded rounds. Make sure to lube you cases though.

 

[A14]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tdow</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Boncrete</div><div class="ubbcode-body">I'm sure there are others out there if you look, but off the top of my head I know Forster makes a die that will do this.

You can neck size and bump the shoulder, and if you only want to bump the shoulder, you just remove the bushing and you are ready to go. </div></div>

^^^This. Forster Bushing Bump Neck Sizing Die. </div></div>

Yes, but unfornately not one for .338LM

 

[A14]

Re: Shoulder bump question.

Bump

 

[X-fan]

Re: Shoulder bump question.

You are concerns about case life with a (quality) full length sizer are unfounded.
The vast majority of what the die does is bump the shoulder.
A properly setup full length die bumps the shoulder just enough for smooth chambering and will not reduce case life.

 

[Tripwire]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: X-fan</div><div class="ubbcode-body">You are concerns about case life with a (quality) full length sizer are unfounded.
The vast majority of what the die does is bump the shoulder.
A properly setup full length die bumps the shoulder just enough for smooth chambering and will not reduce case life. </div></div>

This.........

 

[BuzzBoss915]

Re: Shoulder bump question.

Ditto, I was ready to say the same thing, and this is what I mean about the trends that show up here on the hide.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">No I mean without full length sizing. I am only neck sizing my brass for extended life. Hornadys new line of neck bushing dies bump the shoulder back without sizing any of the body. This is what I want.</div></div>

Where do they get this stuff? (no offense) Neck sizing only won't extend case life, so far as I know? And, I began looking at neck sizing with a critical eye, quite some time ago. The bushing dies are my go to, for all precision handloading, but for general purpose deer hunting, stuff like that, a shoulder bump with a full length die is perfectly satisfactory.

The main thing is, understand why somebody is using a special purpose die. These things aren't for everyone and knowing why a certain die is being used is important and necessary, to keep one from doing something just because somebody else is doing it. These specialized dies have a purpose, but in terms of being essential; not so much.

I do a lot of benchrest inspired steps in my brass preparation, some of it is completely anal and I know it doesn't help a lot for blasting squirrels, but at least I understand, (somewhat) the law of diminishing returns.

 

[shoot4fun]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: EROCO</div><div class="ubbcode-body">To bump the shoulder back you either need a full sizing die, or full sizing die with bushing, or a body die which does not have any neck sizing.

I dont think you can bump the shoulder back any other way.

</div></div>

Wrong!
Please read the parts about using Redding or Forster bump dies.
I use the Forster in a couple of calibers. It allows me to resize the neck with a bushing and slightly move the shoulder back. But bump sizing is only worth while if you can accurately measure your headspace and how much you bump the shoulder back.
You can get pretty much the same effect by setting up a FL die to partial FL size.

 

[Tripwire]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">
You can get pretty much the same effect by setting up a FL die to partial FL size. </div></div>

I laugh when I see this terminology.....partial FL, okay, whatever.

Come on, to even touch the shoulder with a FL die the brass is effectively full length sized, due to the pure mechanics of what's going on in there...to "partial" size with a FL die not touching the shoulder would only reduce neck diameter and leave the brass too long for correct headspace. Once you begin to bump that shoulder the case body itself has been returned to specs. I use ONLY full length dies and set them up to bump .001" with annealed brass. Maybe that's "partial" to some but it's a flawless feed/function and great accuracy for me.

Can't wrap my brain around the need for anything more complicated than that................

 

[shoot4fun]

Re: Shoulder bump question.

The last sentence was put there for a reason known only to me.
It was not meant to fire You up (someone else maybe).

 

[Tripwire]

Re: Shoulder bump question.

I read it at face value, and responded accordingly....my apologies?

 

[shoot4fun]

Re: Shoulder bump question.

None required.

 

[BuzzBoss915]

Re: Shoulder bump question.

Yeah, but that's what I do and what I call it, if it's incorrect, I'll go ahead and take the blame. Don't be mad at shoot4fun, he's just an old fart like me.

BB

 

[A14]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BuzzBoss915</div><div class="ubbcode-body">Ditto, I was ready to say the same thing, and this is what I mean about the trends that show up here on the hide.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">No I mean without full length sizing. I am only neck sizing my brass for extended life. Hornadys new line of neck bushing dies bump the shoulder back without sizing any of the body. This is what I want.</div></div>

Where do they get this stuff? (no offense) Neck sizing only won't extend case life, so far as I know? And, I began looking at neck sizing with a critical eye, quite some time ago. The bushing dies are my go to, for all precision handloading, but for general purpose deer hunting, stuff like that, a shoulder bump with a full length die is perfectly satisfactory.

The main thing is, understand why somebody is using a special purpose die. These things aren't for everyone and knowing why a certain die is being used is important and necessary, to keep one from doing something just because somebody else is doing it. These specialized dies have a purpose, but in terms of being essential; not so much.

I do a lot of benchrest inspired steps in my brass preparation, some of it is completely anal and I know it doesn't help a lot for blasting squirrels, but at least I understand, (somewhat) the law of diminishing returns.

</div></div>

I have read plenty of articles and posts here about full length sizing working the brass hard... As I am sure there are some to the contrary. I can see it over working he brass especially after expanding after the ~3 or so firings until it needs a bump. Obviously there is not a way and this thread has just become about the way you do things, but I doubt you use a $5 bullet to kill squirrels.

 

[BuzzBoss915]

Re: Shoulder bump question.

Maybe not, but I am not into targets. All my application is for hunting something. I develop a load on paper and after that, it's live targets.

I could say the same thing: I don't "doubt" it, but the concept of punching paper with $5 bullets? (roll eyes) Whatever blows your skirt up? Okay by me. BB

 

[MitchAlsup]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">Come on, to even touch the shoulder with a FL die the brass is effectively full length sized, due to the pure mechanics of what's going on in there...</div></div>

Adding:: In order to push the shoulder back, you have to exert enough force on the shoulder for the brass to flow (48KPSI). In order to push the shoulder back and NOT create huge concentricity errors in the body, the case body has to be fully constrained. For the case body to be fully constrained, all of it has to be in complete contact with the die. Thus, with the exception of the neck, the body die full length sizes the body and shoulder of a case.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">to "partial" size with a FL die not touching the shoulder would only reduce neck diameter and leave the brass too long for correct headspace. Once you begin to bump that shoulder the case body itself has been returned to specs.</div></div>

As the case is inserted into the die in the press, the buldge down near the web is compresses radially, this causes the body wall to lengthen and push the shoulder farther outward, then in the last 3 thousands of insertion, the shoulder is bumped back. Actually, brass brom the case wall flows up into the shoulder while brass from the shoulder flows up into the neck.

So, neck sizing with a FL die will partially size the case body along wth the neck, often pushing the shoulder forward in the process. Especially if you have a "generous" factory chamber, less so if you have a nice tight PALMA 95 chamber.

 

[X-fan]

Re: Shoulder bump question.

Interesting thoughts Mitch.

I never considered that neck sizing would alter anything else, but it seems logical that if we make the brass smaller it must go somewhere.

Not sure, but I don't think I generate anywhere near 48,000SI when sizing a case..maybe in the last few thou of the press stroke?

 

[MitchAlsup]

Re: Shoulder bump question.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: X-fan</div><div class="ubbcode-body">Not sure, but I don't think I generate anywhere near 48,000SI when sizing a case..maybe in the last few thou of the press stroke? </div></div>

Consider the number of square inches of brass around the top of the case just before the shoulder. Maybe 20 thou thick and 0.454 in diameter. This gives us 0.027 square inches of brass. Now consider the lever arm 16" long with 1.5" on the other end, giving 12:1 advnatage. So to apply 48K PSI to this brass, we would need to push down on the lever arm with 109 pounds of force.

This seems about 2X-3X what I apply on my press when body sizing (pushing the shooulder back), but we are in the right ball park. Perhaps the brass flow averages a smaller diameter as the sholder flows from the body to the neck. But still we are in the right ball park.

 

[X-fan]

Re: Shoulder bump question.

I was thinking about this today and was considering that we take a vertical force (from the press) and transfer that to a horizontal force (via die taper) to the neck and case body. The biggest power consumption is moving the shoulder back and this takes place int he last few thousands of a an inch of press travel (where the mechanical advantage of the press is at its greatest). Not to mention the shoulder is at 30 degrees (or so) which should ease the pressure required.

Either way there is some serious pressure is at work in the last bit of press travel.

 

[shoot4fun]

Re: Shoulder bump question.

Mitch, X:

You guys are starting to sound like an article from The Varmint Hunter Magazine.
Two "old guys" trying to impress us all with your knowledge of metallurgy, physics and other sciences.

You need to shoot more and split atoms less!