4Mesh - "pre" work-hardening brass

Charles E

curmudgeon
Phil,

I'd asked you about this before, and as I remember, you said you have a 50-ton punch press & some dies your brother made.

I looked in the closet off the living room, and no luck. I didn't see a punch press, so I forgot about it.

But it is winter now.

How important is the wham-bam application of force, anyway? If you size the base slow (compared to a punch press) in a home-made small base die, Does that get you anything?

I can make a die & just push the case through in in a Rockchucker . . .
 
Charles,
What I've done to bases could probably be done with a die-set and a big hammer. It's not moving the brass a long distance, but it is moving all of it. No, I do not think making a die and pushing through will do what you're looking for. It might work harden the surface a bit, but it'll never do anything to the center of the base at the primer pocket. Also, I've done that in the past, or tried to, you'd be surprised what it takes to push a case through a die (if the die isn't the thing that's giving). Mister, yer ask'n for a lot from a Rockchucker! If you did apply enough force to actually form the case, remember, you'd be pushing on it axially, not diametrically. So if you did form it, you'd probably be closing the ejection groove more than anything else since that is the weak spot.
 
When I was using Norma brass and had the primer pockets loosening up on me I did what 4Mesh is describing.You can order the die from CH4D by telling them the exact dimensions you want.The 50 BMG shooters routinely run military pulled down bullets through a 0.5095 sizing die in order to make them round again.
I used a press commonly found in an automotive shop for pressing bearings and universal joints to run the brass through the die as my 80 pound Corbin wasn't up to the task.I was able to remove the belts off of the brass or severely smear them.A mattress was used to catch the brass as it would fly out of the die and dent the necks.
If your case has a belt I doubt you will gain any useful case life by pre-hardening with a press.If it doesn't have a belt measure your brass very carefully as the die runs $125 and you need a 1-1/2 inch threaded press for best results.You can order up the 7/8 inch dies but they flex too much.
They are listed under base forming dies or bullet swaging dies on the CH4D website.
Lynn aka Waterboy
 
I think Lynn means 1-1/4"-12 dies, as with a Rockchucker with the insert removed. And yes, the 7/8" dies are worthless for serious forming work. They just split or stretch, they're not up to the task with so little sidewall.

Lynn, did you ever try that arbor press arrangement with something like a WSM or smaller?
 
4Mesh
I don't use a Rockchucker type press.
RCBS makes a press for the 50 bmg called the Ammomaster with a seperate top plate and Corbin sells a Mega-Mite press at 80 pounds and both of these use the 1-1/2 inch dies common to the 50 bmg and 20mm Vulcan/Lahti rounds found in extreme longrange shooting.If you have a smaller press like the Rockchucker or Lee Classic CH4D sells dies to fit that but you won't be able to shrink your bases a full 0.005 like you can with the big presses.
On my Corbin I put it in the short stroke mode and use the optional long handle.The press works just fine but it bends the reloading bench so much I switched to the hydraulic press instead.

I have not used an arbor press for anything other than seating 6Dasher bullets with Wilson type dies and I sold the press after not liking the set-up.
Happy Thanksgiving to You and the shooters from Williamsport.
Lynn aka Waterboy
 
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Lynn,

1st, I was not aware that the ammomaster was 1.5" vs 1.25. Correction noted.

By arbor press, I meant when you said about the automotive shop press (which also could have been an arbor press, but in your case, might have been an A-frame type).

Happy Thanksgiving to all ya's on the left coast too.
 
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