Let's make a better expanding die

fiver

Well-Known Member
yes.^^^
bind the case central to the bore of the die, then open the neck.
Ian, it's like the neck up procedure I used with the punch in the size die you told me about.
out of 50 I had like 3 that were over .005 OOO the rest were well under that and closer to .003 that was with a sloppy punch and a hammer opening the necks.
an aligned punch into an aligned hole should produce .002 at the outside.
 

Ian

Notorious member
OK, so tell me how you're going to bell the case mouth in a fixed-support setup? Separate step? What keeps the bellmouthing step from going wrong?
 

fiver

Well-Known Member
if your supporting the case and holding the shoulder straight all you can do is limit the neck expansion.
adding a flair is another direction.
you could however put a slight step there to match your bullet diameter.

you know how I flair a case [if I flair one]
 

Intheshop

Banned
My concentricity #'s,once the search was on,looking for issues got noticeably better with planned parenthood.....AKA,annealing.

But now,there's an observed(reading too much BR "stuff") need for a tool to check annealing. Said only,partially tongue in cheek.There has to be an accurate way to check your work.Shooting groups as a testing procedure may seem to be the final word but,it borders on uncontrolled because of the "drivers" and conditions.
 

Ian

Notorious member
The problem I'm trying to solve is keeping a neck in the center of the chamber with only 1/2 thousandth clearance all the way around. And still bump the shoulder two thousandths every reloading and maintain 1.5 thousandths neck tension.
 

fiver

Well-Known Member
and to push all the bad out instead of in.

I think we are working on kind of the same thing here.
I'm planning on the chamber walls bouncing the case back into play.

how about a real long tapered rod combined with the sliding sleeve only the sleeve hits a stop and bumps the shoulder back as the press cams over, then the rod is pressed down to do the neck.
all of this is assuming a previously neck sized case.
 

Elkins45

Active Member
OK, so tell me how you're going to bell the case mouth in a fixed-support setup? Separate step? What keeps the bellmouthing step from going wrong?
The neck clearance once in the die maxes at the diameter of the bell. The belling centers in the die as the punch expands the next into the die walls. Done.

The trick here is to make sure the neck and case body are truly concentrically centered in the die itself.
 

M3845708Bama

Active Member
OK, so tell me how you're going to bell the case mouth in a fixed-support setup? Separate step? What keeps the bellmouthing step from going wrong?
You missed my point about wanting multiple dies. I use turret heads and a dedicated die at each station, so yes I would have to buy an additional complete die for each caliber. Same thing with progressive press tool heads. If you batch-load on a single-stage press, buying the internals from Forster to modify and swap back and forth within the same die body makes sense.

The Lee sizing dies are hard as coffin nails and are wholly unsuitable for machining on a hobby lathe, so I'd have to say that might be impractical, but still a good idea.

You did give me an idea, though.....rather than having to have a chamber reamer for each die....just wax a sized case and mould a rough-bored steel insert with JB Weld. This would allow a fire-formed, neck-only sized case to be used for exact fit, or a FL sized case that's loose in a chamber.

Here's what I had in mind:

View attachment 5434

See how the expanding spud and sliding case sleeve fit together? That interface would be close-tolerance to eliminate wiggle or lateral movement and force the neck to be in the center of the body. Making an arrangement where the sliding sleeve doesn't interface with the expander, but fits closely in the die body and has the plug securely held in the center of the die by large-diameter, close-fit threads, would also work but I think require more precision to make.

Ian, I have friend who makes knives, I had him to aneal a batch of old odd die I picked up for $.25 each at a flea market. A lot of them were Lees. He anealed and they cut like warm butter. in fact all in the group cut great with smooth finish so if you can find someone with heat treat furnace machining is not a problem. The drawing is similar to the old hearters/ C&h seating dies I use for bore rider bullets. I usually get off evil bay. For 6x45 I use .223s and borethe portion above neck out for the bore rider diameter and make a new seater plug to fit. In this case if that same area was bored out to slightly larger than the outside of the desired neck flate and a seater screw turned toexpand neck and flare it would be centered and should accomplish what yall are after. Just a thought. Might be a cheap way out.
 

Rcmaveric

Active Member
If i size the case neck down to only what i need to fit the bullet, is it then necassary to even expand or flare the case mouth? You could buy a few expander rods and turn it down to the diameter your need. Measureing the amount of case neck resize needed then polish the neck area of the sizer to reduce the amount resize and work on the brass. Then back off back off the Full Size case resizer so it doesnt touch the shoulder and your only sizing the neck.
 

Rcmaveric

Active Member
The only way to ensure concentrity is if one thing is fixed and evertthing else self centers on that fixed point.
 

VZerone

Active Member
Ian there's nothing to see. All you would see if I photo the sleeve is that it would look like it was for a 358 Winchester as the hole for the bullet and the bullet seating plug is larger now and I used a larger hole and matched the expander to a snug fit to that hole. I drilled and tapped the back of the plug to accept the Forster seater stem thread size and that's all there is too it. Really only took a few minutes to make it. I still think it's the easier and most accurate way to go.