thickness of jacket material

[257]

hi when looking at corbins sight they list there jacket stock at .030 thickness when looking on sight's on the web every body list's .032 copper will the extra .002 cause a problem when making jacket's with a set of corbin die's the reason I ask is the suppliers sell the .032 for a lot less than corbins any thoughts on this would be appreciated thank's

[knifemaker]

I would think what you are intending to use the bullets for will play a big role concerning the jacket thickness. I know the original Barnes bullets used a jacket thickness of .30 for their big game bullets that were known for deep penetration and holding together. I would not worry to much about another .2 in thickness when dealing with that heavy jacket thickness. Give it a try and test them out.

[aaronraad]

hi when looking at corbins sight they list there jacket stock at .030 thickness when looking on sight's on the web every body list's .032 copper will the extra .002 cause a problem when making jacket's with a set of corbin die's the reason I ask is the suppliers sell the .032 for a lot less than corbins any thoughts on this would be appreciated thank's

This depends on what you class as a problem?

I'm investigating jacket production at the moment and a die set is pretty much designed around the physical properties of a particular feedstock. A change in the feedstock will result in a change in the finished draw at each stage. Sometimes this isn't notable, other times it's significant and might require extra processes to avoid making scrap, let alone something that resembles your previous batch.

Regardless of your supplier, you need a really good definition of what you are getting and then details on the batch tolerances. Anything less, makes die & punch tooling adjustments to suit near impossible.

The investigations I've made so far certainly enlightened me as to origins of the phrase run-of-the-mill.

[MIBULLETS]

Most of Corbins tubing dies were made for .032" thick tubing. I also believe his .375 tubing is actually .035" thick. Not sure what diameter you were looking at.

If you are looking at his copper strip, I don't think the extra .002 will be noticed.

[257]

the reason I was wanting .032 thick copper I can by that for about half of what corbin wants for there .030 thick strips for 5 pounds also wondered about clearance on the die with the extra .002 another idea is to run it thru my friends rolling mill and just reduce it down by .002

[aaronraad]

the reason I was wanting .032 thick copper I can by that for about half of what corbin wants for there .030 thick strips for 5 pounds also wondered about clearance on the die with the extra .002 another idea is to run it thru my friends rolling mill and just reduce it down by .002

Certainly worth running a trial through your friend's mill. You just want to make sure that's it's still within you limits of hardness and that it's not inducing any significant thickness variances etc. over the stock material.

[jmcburn]

Odds are you will not have a problem with the .032 material. More than likely the jacket will just get longer very slightly because the tools are just gonna push the extra material out. Plus idk what the variation from one end of the strip to other end is allowable on such small amounts. I wouldn't be surprised if you got it and it mic'd smaller than .032 especially if it is sold by the foot.

Would you mind linking us to the product?

Edit: Looking at manufacturer specs the on thickness vary from +/-.0005 to +/-.004 depending on what the sheet was supposed to be used for originally. More than likely it will be in the +/-.002 range

[bullet maker 57]

When getting material from suppliers other than Corbin, you have to make sure the copper is dead soft anneal and deep drawing grade. Also you do not want the edge strip.
If you run the material thru a roller to thin it out, it will work harden.
Most standard draw dies will leave you with a wall thickness of .015 unless some other thickness is ordered.

[257]

thanks for the replies I didn't save the searches for copper I just did a search one day and then called different company's the price will vary because it is a commodity with price fluctuations and it is priced by the weight