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Looking for Ideas on Case Forming
5mmgunguy
Member Posts: 3,853
How tough would it be to make case forming dies? I would think the case hardening would be the most difficult. How important would it be to case harden? If you didn't case harden the steel would still be much harder than brass and should last a long time without case hardening.
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I don't know your level of expertise or if you are doing the job yourself or not. Tailgunner states (which is correct) that the steel has to be RC 45. You can't machine with a tool much harder than that with any degree of accuracy. RC 40/45 is about the norm. Case hardening after the die is to dimension has a tendency to warp to a certain degree which you can't do anything about. That you have to live with. Once it's cased you can no longer use any tool on it such as a reamer. You can have it ground but the cost is prohibitive. Cheapest way around this would be to make it very slightly undersized. All this can be done on a GOOD lathe without the use of ANY reamers. When it's done to your satisfaction you can have it flash chromed to approx .0002/.0005 build up on a surface, (more if you have a greater degree of accuracy for the undersizing). Then if you wish you can lap the dimensions with diamond dust. The diamond will not impregnate the chrome when you clean it off. This will produce a very hard and durable and smooth finish, (V-6/15) and the surface will last for years.
Pick up a copy of "The Handloader's Manual Of Cartridge Conversions" by John J. Donnelly. He covers a lot of "conversion" techniques, tools and procedures.
5mm
Pick up a copy of "The Handloader's Manual Of Cartridge Conversions" by John J. Donnelly. He covers a lot of "conversion" techniques, tools and procedures.
Tailgunner beat me to it! This is the modern bible of cartridge conversions. You can make any cartridge without much need for forming dies. With it, and Cartridges of the World, I have created several obsolete cartridges, like the 11mm Murata and 8mm Nambu, and put weapons back on the firing line.
I also aquired a Unimat miniature lathe to turn down rims and cut new extractor grooves. Being a machinist, your skill could be used to make lead bullet molds of obsolete cartridges which I had to have custom made.
Have fun![:D]
for limited use of a few hundred cases. It worked and the dies haven't worn out.
To avoid warping in the case hardening, anneal or stress relieve the metal before machining.
Technically, in the manufacturing sense and for extreme longevity, dies are normally hardened or plated with one recipe or another. I have mentioned before that E-Nickel works for me.
On the other hand, as v35 points out, for some average needs or experimentation, mild steels up to A2 will work just fine even for fairly long runs, at least for us non-manufacturers. I've used 8620 or some variation because it's readily available and easily machined. It can be case hardened if you want. When polished, these dies are very serviceable.
Don't forget that you do not have to make threaded dies for your case forming experiments. Dies used with an arbor press are sometime faster and easier to make and will produce very accurate cases, just ask a benchrest shooter! I have dozens of sets of these types of dies used for cartridge conversions for experiments and making wildcat cases that are not available for general retail. If you take a look at the Wilson Die page, there are some drawings you can use for ideas if you want.
http://lewilson.com/
Threaded die blanks:
http://newlonprecision.com/
Just for reinforcement, you should look at the cartridge conversion books because they have an incredible amount of information in them and they are just plain fun to read. Both books that I have are filled with cartridge case drawings. Dave Kiff has a book of chamber drawing out and it is useful as well.
Best.