Machining molds???

[-06]

Been toying with this idea--why can one not make his own casting blocks? After all, it is just a chunk of steel/Aluminum on a hinge that has been sliced open then drilled/machined and a sprue plate attached. Anyone ever made their own or see it done?

[JIMinPHX]

A few members of this board do make their own molds. NOE makes & sells them. I took a crack at it briefly, but didn't really follow up on it. My exploits can be found here - http://castboolits.gunloads.com/show...ghlight=Blocks

[mr mom]

didnt i just read this on another site ????

[deltaenterprizes]

I have made a few using bought cherry and cherries I made. I have gotten some great advise from members on this board. Do a search the info is still here. The Lyman Cast Bullet Manual shows pics and describes the process. Making the blocks takes a lot of time and so does making the cherry.

Do you have machining skills and tools?

[arjacobson]

I was thinking the same thing until I realized I pay less than $20 for my elcheapo lee molds(with handles) that work GREAT for my kind of shooting. I have some higher priced molds on order though. I am focusing all my attention on machining up a set of .45acp swaging dies. They are expensive and you cannot find them all the time so putting some hours in these will probably benefit me the most.

[deltaenterprizes]

didnt i just read this on another site ????

There is another site? Where?

[theperfessor]

I wrote this about making my own fixturing, tooling, and molds. It's a couple years old and I've improved some tooling and processes since then but it still might be of interest.

http://www.usi.edu/science/engineeri...ulletMolds.doc

[stainless1911]

There is another site? Where?

ammosmith.com is pretty good

[casterofboolits]

Machining your own moulds can be time consuming and difficult depending on the equipment available to you.

When the 41 AE came out, no one made moulds for it. Also, there were no lightweight 10mm boolits (this was before the S&W 40 came out). I have a friend who has a machine shop and would use some of his equipment to match sets of Lyman four cavity moulds to drop the same weight.

One day I was using one of his surface grinders and I was complaining about the lack of suitable moulds for the 41AE, he decided to try to make some. Biggest problem were the blanks for the blocks. I was casting commercially at the time and had taken quite a few Lyman moulds in trade from guys who would rather buy boolits than cast them. We decided to re cut the smaller caliber Lyman moulds rather than make the blanks. I drew up the specs for the cherry and he had a carbide one made by one of his suppliers.

We cut three Lyman four cavity moulds for a 41-165-TCBB and two for a 40-145-TCPB. These were cut with the same carbide cherry on his CNC machining center. The bevel was eliminated on the 40 by not going as deep as the 41.

So for a couple years, I was the only one with a lightweigt 40 and a 41AE boolit. Sold quite a few of the 41's until the 40S&W came out and regulated it to the dustbin of history. The 40-145-TCPB made a nice light boolit for the 40 S&W. I did sell some of the 41's to guys for a light plinking boolit in thier 41 mags.

Still have the moulds and load the 145's for my 40's. I still have a Tanfoglio in 41 AE that I load the 165's for.

[cajun shooter]

A new mold maker Accurate molds makes three cavity brass molds to your specs for $119 to your door. They are machined and not cut with a cherry which I prefer as the cherry cut molds are all depending on the accuracy of the cherry and not the machinst. Dave Farmer of Hoch Molds also machines all of his molds. The Accurate molds are very nice and drop bullets to the grain requested and don't rust.

[deltaenterprizes]

Boring molds limits the designs because the cavity has to be bigger than the tool, CNC is wonderful but has it's limitations.
LEE molds are lathe bored also.

[casterofboolits]

Boring molds limits the designs because the cavity has to be bigger than the tool, CNC is wonderful but has it's limitations.
LEE molds are lathe bored also.

We used a Multi axis CNC machining center and the cherry orbited (?) to cut the cavities.

[machinisttx]

We used a Multi axis CNC machining center and the cherry orbited (?) to cut the cavities.

Circular interpolation is the term. It's also not really making a true circle...the two axis' are actually moving in straight lines to approximate a circle, but the increments of movement are so small that it's nearly imperceptible.

[trap4570]

Here is a simple mold that goes back to paper patch days. It works really well and you can adjust the bullet weight as you see fit. I won't get into a lot of detail, but I have made a few of the molds using only a drill press. Pick a caliber and and look up the appropriate drill in either fractional, letter or number size. Find either aluminum or cast iron bar of an inch or little larger diameter. Steel works ok, but cast iron is better and aluminum is easy to work with. Cut off the bar about 1 1/2 inches or what length you desire and drill the bullet cavity to the depth you think you might use. Use a smaller bit of standard size for threading and bore on through the bar. Thread the smaller hole and screw in a piece of all thread to make sure it screws in freely. Remove the all thread and measure the bore and hone to final diameter using a dowel and emery or wood dowel and abrasive. Take drill rod and cut it off at about 3 inches. It must be bigger than the bullet bore and chuck it in the drill press. Use emery and sand the tip until it fits tight in the bore but moves the bull length of the bullet bore. Next remove the rod and place it in a vise and drill and tap the end - use a bottom tap.- to fit the end of the all thread. Screw it onto the all thread and then cut it off as it is your bullet nose plug. Place this in a vice and take another drill bit and grind it to the nose configuration you want or just select a smaller bit and drill into the end of the plug. You can make your own sprue plate or rob one off another mold. If making your own you will need a transfer punch. If robbing one you will need to sharpen the end of the extra all thread and run it into the mold. Place the robbed plate on top of the mold and center the sprue on the pointed all thread. Mark the points for both the stop and the hinge screw and drill and tap. Attach a handle to the mold and screw the plug into the bullet chamber to the desired depth. If the mold is cast iron or steel - baste the chamber with cold blue. Cast some bullets - they will slide from the mold. Roll the bullets between two rasp files to knurl and either lube in a pan or tumble. You can size first then knurl if you wish. Oh - use a nut to lock the plunger to what depth you wish. If done correctly it will surprise you of the accuracy you will get.

[HollowPoint]

With the knowledge I've gleaned from reading some of the mold-building exploits of some of the more experienced DIY mold makers here I've built a total of 6 different molds.

Although the fit and finish of these molds are nothing to brag about, they have worked better than I expected and each succeeding mold has generally gotten better and better.

To date I've managed to put together three Air Rifle bullet molds and three 30 caliber bullet molds. I'm presently working on my second dedicated 30 caliber paper patching mold. All have been made of aluminum.

I feel compelled to confess that I've also ruined about as many perfectly good store-bought bullet molds as I've built. I tend to learn the hard way.

HollowPoint

[deltaenterprizes]

We used a Multi axis CNC machining center and the cherry orbited (?) to cut the cavities.

It would be kind of hard to do a spire point mold like that.

[JIMinPHX]

Boring molds limits the designs because the cavity has to be bigger than the tool,

The cutter point relief dimension (x-axis) on the lathe bit needs to be greater than the depth of the deepest groove in the finished boolit. To date, I haven't seen any boolit designs that would preclude this method of manufacture. I have never seen a boolit with a groove that was nearly as deep as the minor diameter of the deepest groove. Am I missing something?

[JIMinPHX]

It would be kind of hard to do a spire point mold like that.

With a custom ground end mill, you should be able to pull that off. I do agree that doing it that way probably would not qualify as "easy".

[Doughty]

JIMinPHX

Compression bullets as used in some black powder muzzle loaders. Such as the Model 1856.



Click on the PDF file to see some other examples.

[deltaenterprizes]

Nice looking mold!
I checked out your web site and you do nice work.