Question about drawing 9mm jackets

[MFG_BOP]

Hi guys. I am designing some drawing inserts to make 9mm jackets, about .58" to 0.6" ish tall, 0.352" diameter. I want these jackets to be around 0.011" to 0.015" thick on wall and bottom depending of what I can find around. Any copper alloy. I am also using a robust swaging press designed by me (will increase the handle length tho).

Before jumping in, I have some questions about it.

1 - What disk diameter should I start with? Is 25mm or 1" any good?
2 - Can I reach 0.352"ish diameter cup in one go with this press or should I add one step between?
3 - Stupid one: by my research, copper alloys gauge/thickness is standardized, right?

Of course if I add one in, there will be less effort, but I am taking time account the time.

Any input is appreciated!

Cheers
MFG

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[andrew_six_point_five]

Hi Mfg,

Its good to hear from another jacket maker. I think I can help you on a couple of your questions. My drawing dies are for rifle but the first draw jacket after cup is approx .400 and forms to about .690 in length. I see you are from NZ so you will probably source local copper strip or sheet similar to me over in OZ which is metric unless you can get hold of imported strip from the US. I use easy to get annealed C12200 in 0.70mm but 0.55mm is available. I did some quick calculations and reckon if you start with 7/8" disc in 0.55mm blank you can get a .352" jacket at around .630" in length. You will need two stages, a cup at .476 with a length of .433 and a punch diameter of.433 (LDR ratio 2:1), then the second form die at your .352" with a punch diameter of .316" (allowing for an ironing ratio at 17%). This will get you a wall thickness of .018 and no annealing between the two draws. If you want to get a thinner jacket, you'll need to run a larger punch in diameter (increases the ironing ratio and lengthens the jacket), but this need to be trial and error as the punch can break though if the material is thinned too much. Also consider making a trim die as well. This gets you the 0.6" length you need. All the best in your project.

[andrew_six_point_five]

Attached are images of the cup and first draw dies that will be ok for pistol jackets

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[MFG_BOP]

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