Die Depth

[exdxgxe4life]

I'm having trouble rapping my brain around something that should be so simple...

Why does die depth matter???

My lee single stag press will push the brass up until as far as the shell holder and die meet. If the die is screwed all the way in, the shell holder will will only go up as far until it touches the die. Vice / Versly if the die is not screwed in very far, all I'm doing is pushing the ram further up until the shell holder will will only go up as far until it touches the die.

As long as the top of the shell holder and the bottom of the die meet...why does it matter where the die is in the press??

THANKS!

 

[Ol` Joe]

Die depth matters because you have "flex" in your press that shows when it is under load.
Raise your ram to the top and screw the die in until it touches the shell holder. Now, lube a case and run it all the way in your die and look at the base of the die and the shellholder, you see air?
The dies need to be set to the proper postition to resize the case as needed. You may want full sizing to bump the shoulder back a bit or your chamber/die relation might only require you size the body of your brass partially.
It is all trial and error.

 

[GLOOB]

Other things to consider: If you set the die too deep you can break a carbide die. You might get considerably less leverage from your press if the die is too deep, versus all the way at the top. You can feel the end of the stroke better when it goes all the way. Seating dies for shouldered cartridges may not need to screw all the way down; you may have to adjust for your particular chamber. Expanding dies don't always have to go all the way down. Depends on how much flare you want. Seating dies usually don't go all the way down, either. For progressive presses, you need to make sure all the dies are positioned correctly relative to each other. Because of all of these reasons, it's always better (and sometimes necessary) to index off the end of the stroke travel, rather than the bottom of a die.

 

[exdxgxe4life]

I can understand leverage, but how can I break the die? It shouldn't matter. The brass goes the same distance in the die no matter how high or low the die is. I beg your pardon for my ignorance!

 

[GLOOB]

Carbide dies are brittle. If the shellholder contacts it with too much force, the carbide ring can crack. If you set your die correctly (at the top of the stoke), then your pull ends where the press travel ends. Indexing off the bottom of the die is just asking for trouble. The force is only limited by how hard you pull the lever. Your brass will be fine, but the die might break.

Also, with a shouldered cartridge you might not want the brass to go all the way in. If your chamber is cut large, you might want a few thousandths clearance between the shell holder and die. The only way to do that, repeatably, is to index the die at the top of the stroke.

Edit: Be sure you understand this before you start setting your seating die. Make sure the press is going all the way to the top. It's possible to make halfway decent ammo the wrong way, with the seating die set too deep. What happens is the ram feels like it stops once the case mouth presses on the crimping ring. If your brass and your pull weight are uniform, then the ammo might come out perfect. But if you pull harder, the ram will keep going and start ruining ammo by seating too deep and overcrimping.

 

[JimKirk]

Steel dies ... the ram should be all the way up ...die is screwed down until it touches shellholder... ram is then lowered slightly and the die is screwed an additional 1/4 - 1/2 turn down. This is for normal sizing ... to custom size... adjustments may be made to fit you chamber.

Carbide dies should not touch the shellholder unless they have a protective ring around the carbide insert... some die have this protection ...some don't.

The ram should always be at the top of the stroke for maximum leverage... that is the reason to raise the ram to the top before screwing the die into the press.

Jimmy K

 

[ranger335v]

"As long as the top of the shell holder and the bottom of the die meet...why does it matter where the die is in the press??"

For steel sizer dies, you are correct, it doesn't matter at all how you adjust the die if you are going to push it as far into the die as possible. That's not always wise but as long as you get the cases sized as you wish it doesn't matter how you get there.

It is rare, if ever, anyone needs to fully jam a straight wall case into a sizer and it is possible to crack a carbide sizer ring in some brands.

 

[918v]

With the handle all the way down, and the ram all the way up, screw your carbide sizer to touch the top of the shell holder. The press frame will always spring away from the ram under pressure and will not touch the carbide ring.

Do not set the press to cam over a carbide die. It may crack the carbide.

It is Ok to screw the carbide die deeper, past the cam over point, to get the very last bit of the case sized if you are careful. I do it with my 9mm brass and haven't cracked my sizer yet. But it's pretty hard to do, as the 9mm offers so much sizing resistance and cushions the shellholder from impacting against the carbide.

 

[fguffey]

I use the companion tool to the press. the feeler gage meaning I do not mindlessly crank out full length sized cases because the instructions if followed will have the reloader to adjust the die down to the shell holder with an additional guesstimate of a turn, the threads of a die if 7/8x14 will move up or down .071 thousands per turn (+ a little bit) meaning if there was an index .001 would equal 1/71 of a turn, talking about getting the mind around something, reloaders make guesstimates of a turn rather than go straight to the feeler gage.

In the perfect world brass would be new/unfired, but reloading is not perfect therefore the cases are not alike and do not behave the same. There are times the press wins and sizes the case, other times the case whips the press, not a problem for me with the companion tool to the press, the feeler gage, if the ram does not stuff the case into the die at the top of the stroke some of the case will be preventing the shell holder from contacting the bottom of the die. When this happens (because I do not have a DAY LIGHT or AIR gage/micrometer) I use the feeler gage to determine how 'tuff' the case was/is. There are gages that are/has and can be used to measure flex and deflection. I have strain gages and deflection gages, for those that work with dial indicators they can sit-up one on a press if they have two they can sit up one on the bottom and one on the top just in case the press is spreading and not deflecting or flexing?

As to your question. I would know before I sized a case meaning I determine head space first then size by adjusting the die to prevent sizing more than necessary, others fire first then determine the effect the chamber had on the case when fired AND they call it fire forming, when I fire new case in a chamber I get once fired cases meaning if I need to form cases I form first then fire, and I am the only reloader that can not fire a case by neck sizing 5 times then start over by full length sizing because my cases that have been fired 5 times are 5 firings away from new, means nothing to most reloaders but the case that has been fired 5 times resist being sized because they have been hammered from the inside out, so if you want to 'toughen-up' your cases to resist sizing keep hammering then.

But if I think my cases are whipping my press I use the gage that measures daylight/air, I use the feeler gage to measure the gap between the top of the shell holder and bottom of the die.

I do not say the case does not want to be full length sized to minimum length, I am saying full length sizing may not be necessary, again, I have one chamber I load for that has .016 thousands head space, that is .011 thousands longer than a go-gage chamber from the bolt face to the shoulder of it's shoulder, when sizing the cases the press never flexes, deflects or spreads, meaning most of the abuse of the press is coming from the way the die is adjusted to the shell holder.

Then there is the shell holder, like head space I know the deck height of the shell holder before I start, the deck height is .125 that means the bottom .125 of the case is not sized because the shell holder deck height is a bridge, then there is the radius at the bottom of the die and the part of the die that goes dark when sizing, the inside when sizing, does not have to be that way convincing someone the die can be measured is not easy when transfer, standard and verify are not terms in their vocabulary, there are two ways to determine if the die, shell holder and press was successful at full length sizing.

F. Guffey

 

[JimKirk]

Frank ...
Have you ever thought about adding illustrations or photographic depictions to your treatise, most 'how to enchiridion" add those exemplifications to better, better than words, elucidate the procedures that you are using. Being a long time reloader and being reasonably mechanically inclined, I apprehend 99.9% of what you are trying to explicate, however it is feared that the uninitiated may fail to derive the knowledge that you wish for them to aggregate and rather it leaves them instead discombobulated.

 

[k4swb]

It really doesn't matter where the die is set. What matters is consistency.
If you set the die so that is has done its job, nothing more nothing less with the full stroke of the ram you will be more consistent. Presses do not come with pressure gauges so we can monitor to get the same pressure on each stroke so we set the die to do what we think it should while using the full stroke of the handle/ram.At full stroke you should get the most precise pressure on each stroke you can. May not be exactly perfect but as close as is really needed.