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Help bumping shoulder...strange results

czgunner

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Minuteman
Sep 4, 2007
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I shot my 260 Rem Savage today. Barrel is Shilen, not sure if it matters.
I'm using Peterson brass, once fired (today).
I used the Hornady comparator tool and measured my fired cases at 1.624" (arbitrary number, I know).
I've only got a set of Hornady dies, but when I size the brass, it seems to be growing .002". This was repeatable over 4 pieces of brass.
Does anybody know what I'm doing wrong? How far down should I be setting the die?
 
You can keep setting your die lower until it stops growing and you get the bump you want .
So it's normal to "grow"? This is the first time I've used the comparator tool. For my other ammo I've just been setting up the die per the manufacturers instructions.
 
So it's normal to "grow"? This is the first time I've used the comparator tool. For my other ammo I've just been setting up the die per the manufacturers instructions.
Yes it will get longer before it gets shorter. Your die is stretching the brass out a bit when sizing
 
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So it's normal to "grow"? This is the first time I've used the comparator tool. For my other ammo I've just been setting up the die per the manufacturers instructions.
No, what is probably happening is you are squeezing the sides of the case with the die without the shoulder being
constrained by the die. Its like play dough. You need the screw the die closer to the shellholder so that the shoulder is pushed back.
 
So it's normal to "grow"? This is the first time I've used the comparator tool. For my other ammo I've just been setting up the die per the manufacturers instructions.
No, what is probably happening is you are squeezing the sides of the case with the die without the shoulder being
constrained by the die. Its like play dough. You need the screw the die closer to the shellholder so that the shoulder is pushed back.
Sorry on my post. Yes this is what I’m referring to. Brass stretches (or better word maybe “flows”) to the shoulder area

I set mine up and continue to come down on the die until I achieve about .002-.0015 bump. Then test in the gun to confirm
 
Think playdough, you squeeze it and it’s going squirt up and out as space gets constricted (until it hits something such as the die shoulder to divert its squeeze)

Just screw the die in a smidge more
 
Thanks everybody. I got it dialed in.

One last question: Is it work dumping the Hornady die for a Forster if I have lofty goals of shooting to 800 yards?
 
Thanks everybody. I got it dialed in.

One last question: Is it work dumping the Hornady die for a Forster if I have lofty goals of shooting to 800 yards?
I use Lee collet die/Redding body die for mine. Excellent combo

Personally I’d always choose forester over hornady for dies. But hornady may have got better and if you’re achieving consistency then probably no reason to switch
 
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Thanks everybody. I got it dialed in.

One last question: Is it work dumping the Hornady die for a Forster if I have lofty goals of shooting to 800 yards?

A die is a fairly uncomplicated hunk of steel... some will tell you a $600 die is what you need, but you can buy a Lee die for $20 and shoot half moa groups at 1250 yards (I know because I've done it). I have dies from LE Wilson, Hornady, Lee, Redding, and Forster... they all make great ammo. Different brands will just have slightly different features which you may prefer (or not).
 
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Thanks everybody. I got it dialed in.

One last question: Is it work dumping the Hornady die for a Forster if I have lofty goals of shooting to 800 yards?
Which Hornady set do you have? They make custom grade and match. Their match sizer is excellent, and uses standard bushings for the neck.
 
If you like being able to adjust the bump, here is a technique.

buy these shims
put the .008 shim under your die lock ring.
Adjust die and size cases until the the brass is being sized to the same as the chamber*
lock down the die lock ring**

If you want a -.001 bump use the .007 shim. If you want -.002 bump use the .006 shim. ***

* if the die is set too high the brass will get longer. Keep adjusting tighter until the brass gets longer then keep adjusting tighter until it is sized back go the chamber length. Stop there.

** I use the Hornady lock rings. They have flats so I can use a torque wrench. If you torque the die, that gets the die the same depth every time. I have since noticed that if I just tighten by hand then apply a little force with an adjustable wrench, it is almost as accurate - the torque wrench appeals to my OCD.

If you don't lock the ring, you have to go through this exercise every time. With a locked ring, drop on the shim, screw the die into the press, tighten, measure a case, size a case, and check the bump. If you miss by .001 or .002 - unscrew, new shim, tighten, size cases.

*** When trying to get very uniform bump, it helps to anneal your brass first. Annealed brass is softer and softer brass flows where you want it more consistently. I anneal all precision brass after every firing. YMMV. With annealing I usually get bump either exactly what I want or +.001. Without annealing, it is more like -.001 to +.003 - hard brass doesn't flow well.
 
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So a little explanation might help here. When fired the case body expands and the case/shoulder is stretched to fill the chamber. As the pressure in the chamber decreases the brass will spring back to something but not to its original size. When you resize the body of the case is resized first so the shoulder moves up until the shoulder portion of the die contacts the shoulder and essentially reforms the shoulder and neck. As they say think play dough!
 
If you like being able to adjust the bump, here is a technique.

buy these shims
put the .008 shim under your die lock ring.
Adjust die and size cases until the the brass is being sized to the same as the chamber*
lock down the die lock ring**

If you want a -.001 bump use the .007 shim. If you want -.002 bump use the .006 shim. ***

* if the die is set too high the brass will get longer. Keep adjusting tighter until the brass gets longer then keep adjusting tighter until it is sized back go the chamber length. Stop there.

** I use the Hornady lock rings. They have flats so I can use a torque wrench. If you torque the die, that gets the die the same depth every time. I have since noticed that if I just tighten by hand then apply a little force with an adjustable wrench, it is almost as accurate - the torque wrench appeals to my OCD.

If you don't lock the ring, you have to go through this exercise every time. With a locked ring, drop on the shim, screw the die into the press, tighten, measure a case, size a case, and check the bump. If you miss by .001 or .002 - unscrew, new shim, tighten, size cases.

*** When trying to get very uniform bump, it helps to anneal your brass first. Annealed brass is softer and softer brass flows where you want it more consistently. I anneal all precision brass after every firing. YMMV. With annealing I usually get bump either exactly what I want or +.001. Without annealing, it is more like -.001 to +.003 - hard brass doesn't flow well.
I’m guessing that you are a benchrest shooter and that is why you recommend headspace sizing the same as the chamber length. Of course you are not wrong for that discipline, but for those that are shooting something different and more dynamic, feeding is more important and thus why we tend to recommend 0.0015-0.002” less than fired case (chamber length).

To the OP, good for you in buying the comparator and measuring equipment. The die manufacturers instructions for setting the die are just the starting point for precision reloading, as you are finding out. There are some excellent articles right here on SH that can bring you up to speed quickly. I’ll go get links to a few of them to get you started and post them in a bit.
 
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There are two more articles in this series, but you will have to scroll down towards the bottom of the page to find them.

Good luck on your journey.
 
I’m guessing that you are a benchrest shooter and that is why you recommend headspace sizing the same as the chamber length. Of course you are not wrong for that discipline, but for those that are shooting something different and more dynamic, feeding is more important and thus why we tend to recommend 0.0015-0.002” less than fired case (chamber length).

To the OP, good for you in buying the comparator and measuring equipment. The die manufacturers instructions for setting the die are just the starting point for precision reloading, as you are finding out. There are some excellent articles right here on SH that can bring you up to speed quickly. I’ll go get links to a few of them to get you started and post them in a bit.
I agree on feeding, I have the same problem. You didn't read my post. I said:

If you want a -.001 bump use the .007 shim. If you want -.002 bump use the .006 shim.

If you want a minus one thousandth bump, use the .007 shim. Remember, I had him start with a .008 shim and then adjust the die until sizing matched chamber length. So using a shim that is .001 shorter than .008 makes the shoulder .001 shorter than chamber length. Using a shim that is .002 shorter than .008 makes the chamber .002 shorter than chamber length.

I was a benchrest shooter and lots of my technique comes from there. But for PRS I had to adapt.
 
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JMHO, but dicking around with shims to set shoulder bump sounds like a terrible idea.

One of the main tenets of reloading is achieving consistency and repeatability... adding extra variables like cheap shims that can be problematic, instead of just getting ahold of a die that can be set up correctly, goes against that ethos.

Set your die to bump your longest fired cases by your desired amount (say 2 thou or whatever) and lock it down, sooner or later after enough firing/loading cycles the shorter cases will grow and eventually, they'll all end up the same.
 
Shims between die and press, feeler gauges between case and shell holder and then competition shell holders have been employed for a long time by people who treat each piece of brass as an individual rather than that treating each to the same steps.

tomato tomato. potato potato.
 
I've used the "Skip's" shims for a number of years. They seem to work well. I bought s set of the Redding Competition shell holders and use them most of the time when I need to adjust bump.

I use the Skip's shims now on my Giraud case trimmer if I wish to change the trim length without moving the lock ring. Also works well.
 
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JMHO, but dicking around with shims to set shoulder bump sounds like a terrible idea.

One of the main tenets of reloading is achieving consistency and repeatability... adding extra variables like cheap shims that can be problematic, instead of just getting ahold of a die that can be set up correctly, goes against that ethos.

Set your die to bump your longest fired cases by your desired amount (say 2 thou or whatever) and lock it down, sooner or later after enough firing/loading cycles the shorter cases will grow and eventually, they'll all end up the same.
To each his own. My combination of techniques gives me very consistent headspace. I can't think of a technique that works better than that.

For what's worth, I select a tool based on its utility and fitness to a particular purpose, not it's cost. In my opinion, "cheap" and "works really well" is a good combination.

Right, wrong, or whatever, "consistent" is what all we seem to value so, for me, this is one less thing to blame for non-center hits.
 
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JMHO, but dicking around with shims to set shoulder bump sounds like a terrible idea.

One of the main tenets of reloading is achieving consistency and repeatability... adding extra variables like cheap shims that can be problematic, instead of just getting ahold of a die that can be set up correctly, goes against that ethos.

Set your die to bump your longest fired cases by your desired amount (say 2 thou or whatever) and lock it down, sooner or later after enough firing/loading cycles the shorter cases will grow and eventually, they'll all end up the same.
Try them , not trying them before you say its a terrible idea makes your opinion null and void...and foolish .

EDIT : Cheap shims ? How much should a precision shim cost ?
 
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Try them , not trying them before you say its a terrible idea makes your opinion null and void...and foolish .

EDIT : Cheap shims ? How much should a precision shim cost ?

Different strokes for different folks I guess.

My opinion isn’t stopping you or anyone else from using those shims if that’s what you want to do.

I’d rather just screw a die down until it does what I want, lock it down, not have to mess with it again.
 
Different strokes for different folks I guess.

My opinion isn’t stopping you or anyone else from using those shims if that’s what you want to do.

I’d rather just screw a die down until it does what I want, lock it down, not have to mess with it again.
That’s fine. Just want to point out that shims are used everywhere in custom precision work.
 
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That’s fine. Just want to point out that shims are used everywhere in custom precision work.

I have a set of Skip’s shims but don’t use them. I like the Redding comp shellholders. However, the shims do allow you to change the shoulder bump w/o moving the lock ring on the die and they allow you to do this in a very precise way. In fact, Tony Boyer—winner of 12 World BR championships—describes, in his book, how to use them starting at .015” of shims and working in the direction of bump increase.
 
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