.22 derimming die

[Epsilon]

@Andy37
Carbide is the wrong material, and unnecessary. I only mentioned it because of the exalted status that carbide reloading dies occupy. I was given my 9mm set for free, so am not complaining.
There are some very good tool steels available in Durban which may be hardened very well. The choice must be one which
is easy to machine in soft (annealed) state. Some steels are good for this, but others are just plain awful to work with.
You are quite right that the starting point is the point forming die. It requires a nasty little form-tool cutter. The actual point
end is unsupported, so very weak. When work calms down a little, I'll get to my workshop and start on this little blighter.
For .223 it is small, and my eyesight.....
As far as skills go, Andy, a lot of it is merely risking failure and having a go. Machinist is only a hobby for me. I know the basics,
but cannot claim to be expert. Try something new. Success is not always that elusive!

[Andy37]

Not a chance, I battle to change a lightbulb, I d break everything I touched. If you want to come and see a working Corbin setup to get some guidance and measurements, I'm in Durban too. Just PM me.

[Epsilon]

Not a chance, I battle to change a lightbulb, I d break everything I touched. If you want to come and see a working Corbin setup to get some guidance and measurements, I'm in Durban too. Just PM me.

My psychologist asked whether that lightbulb wanted to change? Anyway, my basic die is now machined and hardened.
A few hours of polishing now remain.

[Epsilon]

The polished die is working reasonably well. Went a little wrong with the ogive curve. Mk2 will correct that.
Made a derimming die to experiment with. Works surprisingly well, but mk2 will be a lot better. Amazing what
information one iteration will yield. It needs to be cut with a form tool, like the point forming die. The tapered hole
is a little difficult to do with a single point boring tool of such a small size. I'd rather make a D-bit with the correct
taper, and then cut the hole in the die. The expert machinists might disagree, but I do what I can with my facilities.

[Peter Brian]

Very interesting post.

[Epsilon]

Thanks PB.
The whole exercise has been challenging, and interesting. I am pleased with the results so far.
Days ago I collected the tool steel to make the dies. With a few extra bits and pieces, the whole invoice was nearly R1K!
So much for trying to save on bullet costs. My licence app goes in soon, so I will have plenty of time to make the dies before I can legally reload for the rifle.

[Epsilon]

Andy37
How does the Corbin setup eject the de-rimmed case from the mandrel? In my experience, the two are well stuck together.

[Epsilon]

Grim
Can you share details of your lead wire extrusion setup? Information of lead slug diameter and pressure required to extrude the 5mm or so lead wire

Thanks
Epsilon

[Grim]

My derimming die has a lip that slides the case off the mandrel when it is withdrawn. If I anneal the cases before derimming they stick to the mandrel, and I found that the mandrel needs to be slightly undersized & well polished to function properly.

I extrude 4.5mm wire basically a big (20mm x 150mm) piston, and the slugs are cast to fit in. a 4.5mm hole out the side at the other end, and then you squish it. I cracked a BIG vise experimenting, and my 2ton press doesn't quite do it, but my 10 ton press doesn't battle at all. It also doesn't really notice if things aren't quite lined up, & happily bends them until they are...

[Epsilon]

Thanks Grim
The heavy duty press has joined the list.