Point Form Cutters

[IllinoisCoyoteHunter]

Yep we use CBN for turning and boring quite a bit here. Definitely faster than grinding, but the tooling is $$$ lol. Nothing in small bores like we’re talking about though.

[Willbird]

Yep we use CBC for turning and boring quite a bit here. Definitely faster than grinding, but the tooling is $$$ lol. Nothing in small bores like we’re talking about though.

I did a lot at one job with PCD inserts. Worked with a salesman from Clapp Dico.

PCD poly crystalline diamond is not supposed to be used on ferrous metals because the carbon in the ferrous metal interacts with the carbon in the diamond and IMHO pulls the Diamond particles out.

BUT he said for low speed stuff like older machines in automated manufacture they had used PCD on cast iron and it worked just fine.

I think a solid carbide bar like was modeled up previously would be worth a try...especially using a form tool to rough the cavity...worst case it just does not work.

I thought it was amazing that they were boring holes as small as .03 or so with solid carbide boring bars....they make them even smaller than that too.

The guy who makes point form dies all day is probably LOL because the way he has always done it works great .

Bill

[IllinoisCoyoteHunter]

Main Body of the die


Ogive section of die that threads into press


Assembly to be held together with 3 1.25” long 8-32 SHC

Will turn a .2235 gage pin with the bullet profile to use as an alignment pin for assembly.

[Willbird]

One thing I remember from the multi part carbide die parts we made that were held in due cases is that part of the “body” would extend into the “nose section” if we were talking a point form die. So say 1/16” of .375 would extend into the nose portion then the ogive would start. If we were making a .375 bullet.

They must have done that for a reason. These were bolt header dies I think in most instances.

[IllinoisCoyoteHunter]

I plan on have a very short section of body diameter in the “nose” (ogive) piece that I will use to know when I’m at the right diameter. Then that will get faced off and then surface ground off after heat treat.

[IllinoisCoyoteHunter]

Picked up the form cutter today. Anything’s possible if we get a few guys interested.

[Willbird]

Picked up the form cutter today. Anything’s possible if we get a few guys interested.

That looks really nice. What did they charge you ??

Bill

[IllinoisCoyoteHunter]

They charged me $185.

If we get some guys interested they could make a run. To have the same ogive radius but different land diameters would not be an issue. So if a guy wanted one at .222 and another guy wanted one at .221 it would be no big deal, as long as we stay with in a couple thousandths.

If you design it, they will grind it lol.

[Willbird]

They charged me $185.

If we get some guys interested they could make a run. To have the same ogive radius but different land diameters would not be an issue. So if a guy wanted one at .222 and another guy wanted one at .221 it would be no big deal, as long as we stay with in a couple thousandths.

If you design it, they will grind it lol.

They should last a long time we would hope. Mailing them around to different folks might not be TOO expensive. The small flat rate box is $10.20 right now.

Bill

[IllinoisCoyoteHunter]

I’d be happy to honcho the group buys if we actually have guys interested.

[almar]

I’d be happy to honcho the group buys if we actually have guys interested.

If you dont mind me asking, did you buy the o6 steel online? If so, where?

[IllinoisCoyoteHunter]

I get my O6 from work. It’s off fall from a job we regularly run. It’s getting harder and harder to find.

[almar]

Ah makes sense. I asked corbin yesterday if they still make their dies with graph mo and he said no because it was getting too difficult to purchase and too expensive. They make them from a different air hardening steel now that is better anyway. I wonder if its D2? He says that they make the tip closing punch out of s2 but its much harder to machine than the dies...

[IllinoisCoyoteHunter]

Probably A2. It holds tolerances better in heat treat than most tools steels. You can machine closer to final dimensions without worry of it moving much in HT, which means less work post heat treat.

Yeah I spoke with Dave a few months ago about this issue. I actually prefer to make dies from A2 anyway. The graphite in O6 is nice, but we lube everything that goes in our dies anyway. One huge advantage to the O6 is that it machines like butter in its annealed condition. A2 is bad to machine at all, but O6 is oh so nice to machine.

Probably making the tip closing punches from S7 and yes it is harder to machine than A2.

[Cap'n Morgan]

Why not use a gas nitriding or carburizing treatment? They work on a variety of cheap, easy cutting steel types. As a bonus, the dies will have a tough inner core and very little dimension change due to hardening (nitriding doesn't need hardening at all)

[IllinoisCoyoteHunter]

You absolutely could. But each process still adds heat and distortion is possible. Not to mention gas nitriding is expensive.

[wywindsor]

I'll take a cutter.

[IllinoisCoyoteHunter]

We’d have to garner up some more interest and get a few more guys interested. If no one else is interested I might sell mine after my die is finished.

[jimrk]

Would be interested in a .308 flavor (30 Carbine)

[GONRA]

GONRA made an Eccentric Spindle Indexer that screws directly onto my SB lathe spindle
to grind RADIAL RELIEF onto 1, 2, 3, 4 flute cutters.

Eccentricity is dialed in with 1 inch 40 tpi clamp screws.
Verkpiece (cutter, end mill, tiny number drill, etc.) centering is established optically
with a 40X "milling machine lineup/centering scope" mounted in lathe tailstock.
Grinding is with a Wholesale Tool electric hand grinder mounted on the lathe compound.
Verkpiece is chucked up in a 3/4 shank ER-1, ER-20 or.... commercial collet
mounted on an indexing wheel.

Etc. Etc. Etc......
I know, just lottsa GONRA crapola but it verks Just Fine
Just keep Lathe Spindle Speed down!