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Does anyone have an ideal of the forces needed to full length size a rifle case?

Trboatworks

Diamond
Joined
Oct 23, 2010
Location
Maryland- USA
I am looking for an appropriate number of pounds of force needed for a body sizing die in typical rifle cases.
Two numbers would be enough- for 223 and 300 Win Mag or 30-06.

Thanks
 
What ever numbers you get will be really approximate. Case hardness, head space of the individual rifle, and the size of the chamber a case is fired in could probably make the force needed vary by several hundred percent.
 
I can appreciate that but it really am just looking for an approximate load range- are we talking a hundred pounds, five hundred or 3000?
More?

I am looking into press design and have questions about the mechanical advantage needed to preform the task with a hand press.

Thanks
 
I agree with FredC

Actual chamber conditions would effect the reforming requirement significantly. And the differing case mfg. wall thickness etc. would be a strong influence. Stack up the variables one way or the other, BIG SWING. I've felt it when resizing 308 brass shot from a single chamber.

Bumping back shoulders for a single bolt gun would be an easier target ;-)
 
I can tell you that the arm force I put on the lever of the reloading tool goes from near zero to about 20 -25 pounds.
I would need to run the mechanical advantage through the toggle mechanism to come up with NET numbers, but you could do that also,
 
Stretch on the commercial presses could be measure with a dial indicator. Converted stretch into pound could be done I guess. If you do that do not forget the linkage stretches also. I would have guessed thousands of pounds.
 
This would be pretty difficult to do on most presses as the various pieces usually have variable cross sections which would complicate the calculations. If you had a C-H H press, you could make a straight top bar of uniform section that would be easier to calculate with. Even with that, the die hole would complicate matters.

The easiest way would be to make a smoothbore hole for the die and let it slide against an anvil with a strain gauge.
 
Are there any pellets that deform a known amount with applied force? Kind of like the crusher disks used to measure CUP in cartridges. If not one could measure the pressure to deform a shop made disk on a hydraulic press, then compare it to the loading press. You would get a little error from the multiple steps but it might be reasonably close.
 
Or you could put the sizing die and case under a hydraulic press that has a pressure gauge. Remove the decapping stem first, since you will need that hole to push out the formed case.

On the top of the factors mentioned above, the lubricant used will play a significant role in the force needed.

Paolo
 
Shouldn't this be well established information?

I did a bit of searching around on the net and get no numbers- not even ranges.
The engineers who design presses must know.
Somewhere there must have been lots of guys who have stuck a load cell over a die in an arbor press and have real numbers.
I see some anecdotal stuff- press x is fine for pistol but too weak for rifle or "Get at Rock Chucker- it has the strength to size X rifle cartridge."

What am I missing here- this shouldn't have to be guessed at or calculated.
Right?


The only thing I find so far is reference to load cells over seating dies used by the fussier bench rest guys to confirm neck tension.
They don't even cite numbers.
What I am looking for is load window needed as starting point to design mechanical advantage for a hand press for all reloading needs for rifle.

There should be a bloody table- Load range for each operation for each cartridge type of rifle and pistol.

Or.... this could be a case like so many in manufacturing- the guys who need to know test to find out while Joe public really doesn't know or care.
He has a press which works and that is all he wants to know about it.
 
Are there any pellets that deform a known amount with applied force? Kind of like the crusher disks used to measure CUP in cartridges. If not one could measure the pressure to deform a shop made disk on a hydraulic press, then compare it to the loading press. You would get a little error from the multiple steps but it might be reasonably close.

The copper crush cylinders would work, but they might not register a reading at those forces. They usually start at around 25,000 psi. For this application Lead crushers, (L.U.P.) would be better, they were used for the lower pressures of shotgun shells and black powder loads.
 
Shouldn't this be well established information?


The engineers who design presses must know.
Somewhere there must have been lots of guys who have stuck a load cell over a die in an arbor press and have real numbers.
I would bet the engineers at the companies building presses do know. Call a few and ask for technical help.
I like Paolo's idea of reading directly off a hydraulic gauge if you have the set up. I used to have a 12 ton air toggle press. And I am here to tell you at the very bottom of the stroke when swaging aircraft fittings it was developing a lot more than 18 tons (18 tons was achieved about .030 from the bottom of the stroke). Whatever pressure one of these handloading presses develops at 1/8 from the bottom is a lot higher at the bottom.
 
Shouldn't this be well established information?

Or.... this could be a case like so many in manufacturing- the guys who need to know test to find out while Joe public really doesn't know or care.
He has a press which works and that is all he wants to know about it.

That's my guess. If I was going to design a press I'd reverse engineer a known good design like a Forster Coax or a Rockchucker and fish scale the handle force then plot the calculated load on the die.
 
Oh you know- I am just trying to protect my reputation.
Some old fart will be going through my crap when I'm gone and will say:
"hey- that's a reloading press"
"Not much of one- maybe you could do .22 lr if anyone even did that"....
 
I get we are all DYI guys but with the amount of work involved to make an accurate press that produces Ammo with no or minimal run out
And the fact you can buy a used Rock Chucker with a lifetime warranty for $100 or a premium Forster Co ax for $300 I’d buy over build and concentrate on loading.
I made a new ram for an old herters press I had because the old one was worn and used the old herters shell holders. Turned a piece of 4140 ph and drilled it all the way through for the primers to drop out the bottom. It was still a pain in the ass.
If your still dead set on it there was a guy on castboolits that designed a swage press and built a few. He put the plans and some math on the website I believe they are still there.
 
I get we are all DYI guys but with the amount of work involved to make an accurate press that produces Ammo with no or minimal run out
And the fact you can buy a used Rock Chucker with a lifetime warranty for $100 or a premium Forster Co ax for $300 I’d buy over build and concentrate on loading.
I made a new ram for an old herters press I had because the old one was worn and used the old herters shell holders. Turned a piece of 4140 ph and drilled it all the way through for the primers to drop out the bottom. It was still a pain in the ass.
If your still dead set on it there was a guy on castboolits that designed a swage press and built a few. He put the plans and some math on the website I believe they are still there.

Believe me I know it.
I usually say - don't build it if you can buy it but......

I am a design/build guy by nature- I looked through the offerings and got interested in the evolution of press design.
That got me to the point where I started to answer that question of what makes a good press with a design of my own.
I thought about it a bit and then drafted a design I really like and am working out the nuances of that.

It is just what I do and have always done- In fact it is why I own a fabrication shop- years of self apprenticeship with projects like this.
It makes no sense to build a press but I do enjoy the work so I am still working on the design.

But....... I am watching for a old Pacific single or a Rock Chucker to pop up at a fair price and I will buy one probably before I get one built.
If I were slightly more flush I would just buy the Redding T7 at retail and call it a day.
That sort of closes the discussion loop in a way- my design is along the lines of the old Dunbar H which has a sweet spot in press design to my mind.
I have worked out improved mechanics and would build as a four station press.

The brass is stacking up so I need to get sorted here soon.
 
TRIBOATWORKS

Respect for your intent and efforts.

The trouble with "toggle" mechanisms is that the force at the "work" point can be Very large compared to the input force. It's like hanging a weight on a taught stretched horizontal cable. Reverse engineering is likely the quickest way!

Look at the size of the elements on the commercial units. The lever arm length tells me much.

Wouldn't it be nice if there was a look up table for all this ;-)
 








 
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