Reloading 410 on a metallic press with dies

[mag41uk]

A friend has a hushpower 410, plenty of land, a clay trap, several children and grandchildren!
410 cartridges are expensive.
We spent some time loading some of his fired 3 inch cases using published loads and they work a treat.
Its a ball ache to load time wise. The cases need trimming and resizing, de priming, repriming pretty much the same as a metallic cartridge.
The rim of a 410 fits a 303 shell holder and the brass part is nominally 45acp.
The hole in the shellholder is too small for a shotgun primer to fit through and needs opening out. I believe shell holders are hardened?
I have a pile of 45acp dies to work with but the main problem is they are too short.
A decapping rod/pin for SG primers needs to be about 3mm in diameter.
So this is an engineering exercise for one of you lathe owners!
How feasible is it to extend a decapping/sizing die by making up an extension?
This extension could also be threaded to hold our new decapping rod.
I would also need a device to seat the primers. This could be a bar that fits into the case. This bar could be fitted inside say, a seating die. Then use a block of metal where the shell holder fits.
I am set up for roll crimping which works well.
I don't want to buy a dedicated press.
If any one fancies helping me out on this I am happy to pay your time.

[bewildered]

It sounds like the priming system used on the Wamadet press would be just the job for your cases.

[greenshoots]

use 303 brass there is a 410 site which will show u how

greenshoots

[Dorset_shooter]

Or buy a cheap lee loadall, I think you can get them in 410. Would be super quick to load then.
My 12g loadall cost 25£ second hand

[Chapuis]

Or buy a cheap lee loadall, I think you can get them in 410. Would be super quick to load then.
My 12g loadall cost 25£ second hand

They only make them in 12, 16 and 20 gauge, not in .410.

[mowdy]

You could use .444 marlin brass for the 410 if you wanted to
Mowdy

[Gazza]

use 303 brass there is a 410 site which will show u how

greenshoots

I looked into this and its not worth the cost or effort.
By the time you have used a couple of primers/charges/wads etc to blow the case out to .410 its cost you the same as buying Magtec brass .410 cases and the Magtec ones will be uniform and not just "usable"
Of course if your doing it for something to do then fill ya boots

[mag41uk]

Update.
Thanks for suggestions etc.
I made up a new decapping rod to fit a 50/70 decapping die. Its a long die and the 3inch cases fit easily.
I fastened two different ID washer together that drops over the shell holder holder on my RCBS press for the spent primer to fall through.
I made a rod to fit a Lee universal decapping die to serve as a primer seating tool.
I drilled out a Lee 45acp carbide die and use a 303 shell holder for sizing the brass.
All work a treat.
I have a gaep case trimmer coming which can be mounted in a drill so I can speed up the case trimming.
I converted some 303 cases but the fire forming is problematic with a hushpower shotgun.
Too easy to fill the moderator with semolina! (which you cant remove!)