Teach me about cherries and the mold making process.

[Aloxite]

I've been reading about molds and I am forming an image in my mind of what the "cherry" must look like. I am imagining a piece of high speed steel that has the shape of the bullet nose and sides with the crimp and lube grooves.

But I'm just guessing. I'm curious to see pictures of actual cherries and to hear a bit about how you use one to cut a cavity in a mold. I'd imagine that you would drill out a hole in the mold blocks before using the cherry. Also, I'd think the mold blocks would be chucked into a four jaw chuck on a lathe and the drill bit and then cherry would be held in the tool holder or in the tailstock.

[swheeler]

Open your Lyman Cast Bullet Handbook 3rd Edition to pages 54 and 55, has some pictures.

[John Boy]

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CDYQFjAA&url=http%3A%2F%2Fwww.usi.edu%2Fscience%2Fengineeri ng%2Fmoldfixture%2FMakingBulletMolds.doc&ei=zDL5TrmBFob10gGf342GAg&usg=AFQjCNGgN6rCOYmdIQQxT346v6n_x3lnoA&sig2=Ayj0h87Vfpu8I1MPiGZUlw

[theperfessor]

Don't know if this is of any interest. Its in Word format.

http://www.usi.edu/science/engineering/moldfixture/MakingBulletMolds.doc

[AndyC]

From Miha's mp-molds.com:

http://www.mp-molds.com/index.php?pr=Custom_cherry_cutters

[BossHoss]

Darn,

I thought they were going to be bright red and sugar coated.....not a modified drill bit.

Sorry, couldn't resist the joke, but very interesting and precise. It would seem to me the cutting of the cherry is where all the work is.

[deltaenterprizes]

The part I have not been able to master to my satisfaction is sharpening the cherry after cutting the flutes.

[Cap'n Morgan]

There's a lot of different ways to make cherries. These two are made from solid carbide on a CNC grinding machine. The one on the right is a single flute for maximum stiffness. The left one has two helix flutes which reduces the chances of chatter while cutting. Both are meant to be used as "generic" cherries, meaning they can be used for a large range of different calibers, but, of course, all with the same profile.

http://img4.imageshack.us/img4/8122/img0861op.jpg

[yovinny]

[QUOTE=Cap'n Morgan;1519609] Both are meant to be used as "generic" cherries, meaning they can be used for a large range of different calibers, but, of course, all with the same profile.QUOTE]

So if I'm understanding correctly, you'r plunging and then interpolating to finished diameter. Instead of closing the mould halves around a stationary, full size cutter ?

[fj3fury]

The mold makers probably use a boring bar, that moves the cherry cutters .001" at a time off center. Some one posted a youtube vid where he made one of his own and cut a mold for a gahendra rifle because it was .460" or better.

[W.R.Buchanan]

There are several ways to generate the mould cavity.

An "undersized cherry" like shown above which is put into the hole and then circular interpolated to form the size cavity you want. Done on a CNC mill, or could be done on a manual mill with a rotary table setup.

An "on size cherry" where the mould blocks are closed on the rotating cherry by use of a dedicated fixture. Done on a manual mill with the fixture installed.

And lathe boring by using a boring tool on a CNC lathe.

These are the most common ways to make a boolit mould.

Randy

[leadman]

Lee did lathe bore their molds until about 1 year or so ago. They now use a CNC milling machine to cut each half separately. I think MIHEC also does his this way.

Read an article on cutting a mold with a cherry that was about one half of the bullet. A hole was drilled big enough to allow the cherry to enter the hole and then the cherry was used to finish it. This was done in a lathe.

I think if one was using aluminum to make a single mold the steel would not have to be super hard to cut.

I have a 4 jaw chuck for my little Craftsman lathe and may give it a try someday.

[Cap'n Morgan]

So if I'm understanding correctly, you'r plunging and then interpolating to finished diameter. Instead of closing the mould halves around a stationary, full size cutter ?

Correct. Working with a closed mold keeps the edges in the cavities free of burrs, but the cavities must be cleaned off swarf several times during the process, otherwise the cutter will likely clog and break.

[Aloxite]

Interesting stuff. I hadn't considered using a rotary table on a mill. Thanks for all of the replies.

[grubbylabs]

Wow very informative. Thanks for all the info.

[madsenshooter]

Here's what Don Eagan's cherries looked like:

http://castboolits.gunloads.com/imagehosting/thum_12364efd2204eedb0.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3161)http://castboolits.gunloads.com/imagehosting/thum_12364efd227443787.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3162)