Case Forming for obsolete calibers and hard to find brass

This is intended to get guys to pull some old relic out of the gun case and get it shooting again.

I have now developed some skills in forming brass for obsolete calibers.
And working out what you are actually trying to create in the first instance.

Recently I acquired an Alexander Henry side hammer falling block rifle in 450 caliber case unknown.
the British 450 calibers would likely be the most confusing and crowded caliber space.
We I could have gone and borrowed my friends tin of cerrosafe, but was impatient so I formed some depth gauge rods from 7075 alloy on the lathe and just worked out accurately where the neck and shoulder were.
Looked at Cartridges of the World, asked google a few intelligent questions and deduced it was a 500/450 no2 Musket.
Delightful. That is a pretty useful 450 about half way between a 45-70 and 45-90.
Standard BP load in the day was 80 to 85 Grains of Curtis and Harvey no6 powder.

So how to create a 500/450 no2 Musket case.
I took a 500 3" nitro express case from my precious hoard for my 1885 50 Eley.
Cut to 2.4"
Tidy up case mouth perfectly because its going to be reduced a lot and any imperfection will give it cause to fail at that point.
Anneal to below where shoulder will be.
Apply a smear if imperial sizing wax
Form 450 neck with 577/450 sizing die in my big 1 1/4" press.
The neck forming pushed a bit of an outside doughnut on the neck because the body of the case isn't supported by the 577/450 die
Use a 50-70 Govt sizer die to push the doughnut out of the shoulder.
Test the case in the chamber and fiddle around with the 50-70 die until it is perfect
Trim case to 2 11/32"
Re anneal. This is important because the brass is now work hardened from being formed down from 50 cal to 45 cal
This case is formed to head space off the neck because nitro brass has a 0.5mm thinner rim that the old BPE brass.

When this case was fired with a modest load of 60 grain 1 1/2 FG Holy Smoke the numbers were almost un changed. The base of the neck did bump up a bit.
But the case extracted and was easily re chambered when cold.
So it was very close to perfect.

This is all relatively easy to do if you take the time to deduce what you have and how to get to where you need to be.
I have 33 sets of reloading dies and this does help when trying to find a solution to some of the challenges you will meet.

Here is a line up of formed cases

500/450 no2 Musket from 500 Nitro Express brass

500/450 no1 Express. Original and the next case I will need to recreate

500 3" BPE. Just a standard 500 nitro express case. Blue PC bullet for BPE. Red PC bullets for nitro rounds

577/450 formed from 24 gauge magtech brass. Dummy round hence red nitro bullet

577 Snider formed from 24 Gauge magtech brass. Dunny round with 650 grain flat base bullet

Attachment 225141

20 cases will last a life time with a vintage big bore like these.
So its not that daunting if you take some time and understand what your objective is.
Most of these old big bores can be made to shoot acceptably well and some exceptionally well when you get it right.
Powder coated bullets are a great help in loading full soft lead bullets in these rifle

If anyone needs some help to get one of these relics going, just ask