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How to Fireform 303 Brass into 410 Shells


Fireform 410 Brass

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This post on how to fireform 410 brass shells from .303 British cases is pretty neat.

I don’t know how timely this article is now that you can buy your own brass .410 hulls from midway.  However, it is a project I have wanted to do for a long time.  I even had some new unfired .303 brass.  So I felt it was time to experiment with my old cases.

If you have reloaded shotshells, then you probably know that when using a brass case and normal powder loads the case will last “forever”.  Which makes up for the added skill and effort in loading them.

What we will be doing today is to show how we made .410 brass from a .303 British case.

.444 marlin and 9.3x74R brass can also be used.

I will admit, I got this idea from the End Times Report.  This was not the easiest project I have attempted.  It was harder than it seemed when I read it.

They did briefly mention that while the dies used to form the cases were the same, the heads are a different size.

The .303 brass did fit in the chamber.  However, the chamber did not close properly (without slamming it shut).  Additionally, the brass did not extract properly.

I did find another resource at Surplusfrearm.com that explained what I needed to do to remedy that problem.  Later, I will cut the heads down before I go shoot these shotshells.

But the endtimes report system did work, and it really wasn’t that hard.

First Your Should Take a .303 British Case and Anneal it.

Annealing brass is different than annealing steel. Brass gets work hardened.  The more it is used the harder it gets.  Annealing it by heating it makes it soft and easy to work.  This is the opposite of steel,

To anneal I took a drill and using a screw and a socket I made a small fixture to hold the head of the cartridge. As the drill turned the case I heated the neck of the case using a torch. I heated the case up but took care not to heat the case head (for safety purpose you do not want to anneal the head). Once the case was annealed, I simply thumped it into a container of water.

Next I primed the cases.

At the range I used 11 grains of shotshell powder (blue dot, but I should have used red dot).

Then I added yellow grits (most use cream of wheat, but I had grits on hand.

I added a little bit of toilet paper to keep the grits from falling out (but I did not pack it).

After firing the cases were fire formed to the shotgun chamber and are ready to be cleaned and loaded as shot-shells.

It could have went better, and the video shows that not all the cases formed equally well.

Personally, I like knowing that this can work, but I think I will stick with the actual .410 brass cases.


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