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Shoulder bump jumping all over the place?!

The Durk

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Minuteman
Jun 12, 2013
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Pittsburgh PA
Ok so I’ll start with my equipment:
Forster Co Ax press
Redding FL S bushing die
Hornady one shot case lube
Hornady headspace comparator
Hornady caliper

So let’s start with the basics I did:
Checked all my cases I wished to resize.
When the caliper is zeroed all UNSIZED fired cases run about a .001 variance. That’s it.
Lube the cases lightly with hornady one shot.
Double check one or two cases and it’s still zeroed perfectly with my calipers.

Size one case until I get to .002 shoulder bumps. Tighten the forster die ring down while the cartridge is in the die, as to not disturb it.

I size the next case, and it’s .002 bump.
The next following 2 cases jump .004-.006 bump?!

The press is also making a squeaking sound when it bumps it appropriately, while I try to remove the case from the die. When it bumps it a lot, the cartridge goes in smooth and comes out smooth.

Am I using enough lube? Is it running dry and causing issues? I’m flabbergasted and I’m quite new to making sure the shoulder bump is perfect.

Feel free to reprimand me. I’m not quite seeing why it’s jumping all over the place.
 
I made my shoulder bumping separate operation . After FL /bushing sizing I wipe resized cases of lube and run them through bump die ( no bushing ) 'dry'.
You also have to be consistent with the force/movement when 'bumping'. You'll be satisfied with results . No lube on the shoulders = consistency .
 
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If you don't get enough lube on the inside of the neck, you can pull you shoulder back forward when the expander ball runs through the neck. This unlubricated metal on metal contact makes a squeak sometimes.
 
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👆 that also but I personally not using expender ball at all . I finish necks with mandrel and some dry lube (graphite )on inside .
 
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Ok so I’ll start with my equipment:
Forster Co Ax press
Redding FL S bushing die
Hornady one shot case lube
Hornady headspace comparator
Hornady caliper

So let’s start with the basics I did:
Checked all my cases I wished to resize.
When the caliper is zeroed all UNSIZED fired cases run about a .001 variance. That’s it.
Lube the cases lightly with hornady one shot.
Double check one or two cases and it’s still zeroed perfectly with my calipers.

Size one case until I get to .002 shoulder bumps. Tighten the forster die ring down while the cartridge is in the die, as to not disturb it.

I size the next case, and it’s .002 bump.
The next following 2 cases jump .004-.006 bump?!

The press is also making a squeaking sound when it bumps it appropriately, while I try to remove the case from the die. When it bumps it a lot, the cartridge goes in smooth and comes out smooth.

Am I using enough lube? Is it running dry and causing issues? I’m flabbergasted and I’m quite new to making sure the shoulder bump is perfect.

Feel free to reprimand me. I’m not quite seeing why it’s jumping all over the place.
i have same issue,
 
I have same issue. Haven’t figured it out yet.

Redding type S die. No expander ball to pull the shoulder. 260 rem

Guess I’ll expand on my operation for info sake.

Tumble in rice
Anneal on annealez every firing
Let cool
Spray hornady one shot liberally
Run through die
Check bump with Redding dial indicator

70% bump normal, 30% it’s 4-6 thou

Process for setting up die
-find a once fired case that the bolt closes hard on
-turn die and size very incrementally until the should bumps back enough to where bolt does not close hard, which is .001-.002 bump
 
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Shouldn’t be a squeak. I’m betting if you resize the .002’s they’ll end up .006, raise your die a smidge , lube well, re run
 
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Shouldn’t be a squeak. I’m betting if you resize the .002’s they’ll end up .006, raise your die a smidge , lube well, re run
im not the OP but i did notice if i re ran mine, they bump, not all cases needed this second bump, is this just spring back?
 
Depends on the brass really, Winchester 300 wsm brass is the toughest I’ve ran across. Just got to force it to your will. Thinner brass has its advantages. I don’t get too concerned as long as it’s close and chambers easy
 
I’m using Peterson brass. I’m shooting a match tomorrow so I’ll play with making sure I really spray the cases it well.
 
If you have liquid on the case that has not evaporated yet, from the one shot, it can make your bump jump all over too.
One shot requirements
Shake it like a teenager in the shower after seeing a booby
Apply it like you stole it
Have the patience of a monk waiting for it to dry.

One shot has its uses but if you want to see what a good lube does try some imperial.
 
The key to HOS is to apply an even amount and let the lube dry. The ones where the shoulder bumped more had more lube on them. The ones where the shoulder bumped less had less lube on them. It’s that simple.
 
One shot requirements
Shake it like a teenager in the shower after seeing a booby
Apply it like you stole it
Have the patience of a monk waiting for it to dry.

One shot has its uses but if you want to see what a good lube does try some imperial.
I’ve never waited for it to dry. Will try that next time.

What’s the process for imperial? I’ve been using the one shot because it seemed to be the easiest
 
I’ve never waited for it to dry. Will try that next time.

What’s the process for imperial? I’ve been using the one shot because it seemed to be the easiest
Drying is essential for one shot

I apply imperial lightly along the side of the case below the shoulder then wipe it off after sizing.
 
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Bag full of brass, spray HOS. Close, mix for 45 seconds, open bag to air/dry. I spray the die with a shot too. I use some Imperial on the first few cases, lightly and every 8-10 ish. It's not perfect, however it has never caused a inconsistency issue. Simple, yet works. Redding dies, hornady single stage press with bolt/gas 308/556. Good luck.
 
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Another way to achieve uniform shoulder bump is to convert your press to use shell holders and to bottom out the die on the shell holder. Then use Redding competition shell holders to control the shoulder length.

Just picked up the parts to do this.

Any real negatives to running a shell holder in a co-ax?
 
I agree with the One Shot comments. I have never had good luck with it. I seem to have the best luck with lanolin based lubes that use isopropyl alcohol as the solvent. Evaporates quickly and produces good results. If you over apply it, you will get dented shoulders and goofy setback numbers on the way. There is an application amount ‘sweet spot’. You do need to let the alcohol evaporate.
 
Lanolin Alcohol mix case lube, most certainly does not evaporate, and become ready for sizing "quickly" when compared to one shot. Start sizing before all the alcohol evaporates, which normally takes more than 30 minutes in my experience, and shoulder bump will be all over.
 
The alcohol most certainly does not evaporate quickly. You have to take some time before they are ready to size. If you measure your cases when sizing, you will find out.

One shot takes a couple minutes, IPA and lanolin, I use if I have time to spray my brass down, and go do something else for a couple hours while it drys.
 
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Just picked up the parts to do this.

Any real negatives to running a shell holder in a co-ax?

The shell holder adapter does not have a spring clip to retain the shell holder like your normal press does. Instead it has a set screw. I don’t like that cuz it preloads the shell holder. So I just let it free float. But then it rotates too easily. That’s the negative.

Another positive is you can use the shell holder and the die setting to act as a hard stop instead of the linkage stopping on the bump stops fast into the press.
 
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Just picked up the parts to do this.

Any real negatives to running a shell holder in a co-ax?
IMO, common sense says no. The die still floats, shellholders were designed to self center cases. But as we tell others, run the test and inform us, lol
I have 3 coax's, 1 to size, 1 to seat, one setup for portable use finding seat depth at the range. Blah, blah, the last one came with the shellplate system loose, I just left it loose and though it is tough to gauge gains, I think it helped when seating bullets, but really makes no sense.
 
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" Another way to achieve uniform shoulder bump is to convert your press to use shell holders and to bottom out the die on the shell holder. Then use Redding competition shell holders to control the shoulder length. "

And that is about the size of it, and use Imperial.
 
OP. this is a classic case of non uniform lube, and honestly, you should be able to feel the difference when sizing some of these cases. Your .2 bumps feel stiff, the .4-6 slide into die.
 
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Skip to 21:20


Ok so I’ll start with my equipment:
Forster Co Ax press
Redding FL S bushing die
Hornady one shot case lube
Hornady headspace comparator
Hornady caliper

So let’s start with the basics I did:
Checked all my cases I wished to resize.
When the caliper is zeroed all UNSIZED fired cases run about a .001 variance. That’s it.
Lube the cases lightly with hornady one shot.
Double check one or two cases and it’s still zeroed perfectly with my calipers.

Size one case until I get to .002 shoulder bumps. Tighten the forster die ring down while the cartridge is in the die, as to not disturb it.

I size the next case, and it’s .002 bump.
The next following 2 cases jump .004-.006 bump?!

The press is also making a squeaking sound when it bumps it appropriately, while I try to remove the case from the die. When it bumps it a lot, the cartridge goes in smooth and comes out smooth.

Am I using enough lube? Is it running dry and causing issues? I’m flabbergasted and I’m quite new to making sure the shoulder bump is perfect.

Feel free to reprimand me. I’m not quite seeing why it’s jumping all over the place.
 
Well, I fixed it.
The answer was......more lube than a porn star. Sprayed the crap out of my cases and die with hornady one shot. Let it sit for 5 minutes. 64 pieces of brass all sized to .002 shoulder bump. Thanks everyone for the advice! I’ll be looking at the liquid lanolin mixture next season. This bottle will hold me off until then.
 
Well, I fixed it.
The answer was......more lube than a porn star. Sprayed the crap out of my cases and die with hornady one shot. Let it sit for 5 minutes. 64 pieces of brass all sized to .002 shoulder bump. Thanks everyone for the advice! I’ll be looking at the liquid lanolin mixture next season. This bottle will hold me off until then.
Good to hear.
I personally like one shot more than the homemade lube.
 
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I had a slew of problems with consistent shoulder bump when I first started. I think the 2 most important things I did to get my ES on shoulder bump to .001 was start using lanolin/alcohol case lube and annealing after every firing. Consistent lube from case to case is the number one thing that contributed to the consistent shoulder bump though. I do all of my cases in one lot and lube them all at the same time in a large container. Let the alcohol flash off and size away
 
Hornady one shot has never been enough lube for me when sizing rifle brass. It is perfectly fine for pistol cases. As far a shoulder bump, if your die does not make contact with your shell holder, you are pissing in the wind. That's why I use Redding competition shell holders along with Redding body dies. I size my necks afterwards with a Lee collet die since runout is pretty much non existent and no lube required on the necks.