Thread: 577-450 case forming

So @Rambo6mm has been visiting Akaroa for a long weekend away from the big city

He brought 577-450 dies and 50x Magtech 24 gauge brass cases for us to try case forming in my massive new RCBS rock chucker supreme press

Let's just say its a steep learning curve but easier in a fully resourced workshop

Made special mandrels for trimming and re trimming in the lathe

Lost a few cases early on to rookie mistakes
But we mastered the techniques over time and turned out 43 perfect cases from the 50 we started with

A couple of the rejects can become shorter Snider cases
A couple are just wrecked and cheap learning

The last 20 went through the system without a single failure

Sure its slow first time doing it
But a set of 50 cases will last a very long time

Looking forward to seeing these loaded and sending big bombs down range

They look good!

Keep them annealed and just give the necks a " nip" when you resize them. I have been shooting magtech resized cases for a decade and have only lost a few.

Dont be tempted to use smokeless in them, they just arnt up to that.

Talk about long life, I've still got some SPANZ turned cases that must be over 30 years old and I have no idea how many times they've been reloaded. Mind you they don't hold a full powder charge.

is that a split neck on the middle case I spy????
they look great.

When can I put my order in?
I have the brass

Look smashing

Originally Posted by Micky Duck

is that a split neck on the middle case I spy????
they look great.

No not split
There is a tiny sizer oil release hole in the shoulder of the dies
It leaves a tiny smudge on the forming of every case

No problem
Just cosmetic

Just a note i read online is that these reformed 24g shells ave quite a bit more case capacity than a original say kynoch case
So it is possible to over load them not that that matters too much with black powder
But ideally you should use the maximum of the original charge or lower and fill the rest of the case with filler weather that be wads or corn meal or something

Originally Posted by Boxton

When can I put my order in?
I have the brass

Look smashing

There could be a small scale business opportunity, I brought some Bertram cases a few years ago and they were $10 each, they must be more now.

Originally Posted by rambo-6mmrem

Just a note i read online is that these reformed 24g shells ave quite a bit more case capacity than a original say kynoch case
So it is possible to over load them not that that matters too much with black powder
But ideally you should use the maximum of the original charge or lower and fill the rest of the case with filler weather that be wads or corn meal or something

That makes a lot of sense
The Magtech brass is pretty thin and has a completely different cartridge base

I have Magtech and Bertram 577 Snider brass and I can go measure the volume difference

Originally Posted by Marty Henry

There could be a small scale business opportunity, I brought some Bertram cases a few years ago and they were $10 each, they must be more now.

I'm set up now with all the tooling and dies to form 577 Snider and 577-450

It is fairly involved with all the trimming and annealing
577 Is relatively easy and 100% are perfect

577-450 much more work and you could expect one or two failures from a box of 25

Thankfully I have an automatic annealer which helps a lot because you anneal before and after case forming

If anyone wants some made PM me

So the numbers on case volume are

577 Snider case water capacity

Bertram new brass 120.0 grains

Magtech 24 gauge formed Snider 134. grains ( so plus 10% volume on the Bertram )

Kynoch vintage 122.5 grains ( this is a fired case and will have increased volume on new )

So as @rambo-6mmrem mentioned a lot more case capacity and care and filler required with both the 577 Snider and 577-450 formed with Magtech

On the up side you will have no trouble loading a full charge of BP into these cases and still have space for a grease cookie etc

Originally Posted by rambo-6mmrem

Just a note i read online is that these reformed 24g shells ave quite a bit more case capacity than a original say kynoch case
So it is possible to over load them not that that matters too much with black powder
But ideally you should use the maximum of the original charge or lower and fill the rest of the case with filler weather that be wads or corn meal or something

I would be a bit more specific with that advice.

Alot of blackpowder cartridge reloading tips relate directly to straight walled cases like the 45/70 not bottle necked cases.Where by any kind of filler wont have to be compressed upon firing as it goes from the case size below the neck to a much smaller diameter through the neck,then a even smaller diamter into the bore.From personal experiance using loose fillers like Corn meal or dried coffee grounds you can get a whopping ovepressure if you are unlucky as it can get compressed into a solid shug. Kapok,cottonwood,raw wool,or my favourite foam backing rod are safe and cheap alternatives to loose fillers. Remember to keep your wads in the neck too,they can fall onto the charge more often than you think.

577/450 in a Martini Henry is hands down my favourite black powder cartridge.

Well I'm quite surprised that you can actually re form the Magtech 24 gauge brass to 577-450

It is a massive amount of case diameter change
The new RCBS press has power to burn and does it easily
And they are perfect cases. Actually a lot better that a batch of Bertram 12.7x44 brass I have just spent hours getting the uniform rim and next diameters and thicknesses

Originally Posted by norsk

577/450 in a Martini Henry is hands down my favourite black powder cartridge.

Typically I was forming these for a friend and now I want a 577-450 also and comments like that @norsk are not helpful !

So now I am looking for an AH side hammer 577-450 sporting rifle
Anyone got a spare one ?

Can you source .50 Alaskan brass in NZ? The fireforms to 12x44 easily and is nice and stout should you want to burn a bit of smokeless.