fireforming .410 brass

[wildrover77]

I am fireform 9.3x74r into .410 shotgun brass.

I have put 11grains of alliant 410 into the case then filled it with tissue paper.

I did not want to use cream of wheat as my gun is a semi auto.

will this work ok?

[Ovenpaa]

.410 S/A Shotgun?

A 3" .410 cartridge is 76mm long so the 9.3x74R has the length, I would be inclined to trim the neck back on a couple first to an OAL of say 70mm and try to fire form, it will need less energy to pop the shoulders out this way and will give an indication of how things are progressing within the chamber.

I have packed cartridges with toilet paper in the past without issues but I think it is something you need to experiment with, do you have somewhere local you can try this on or is it off to a range somewhere?

[Sandgroper]

I'm no expert on fireforming, but I suspect not.

I believe the cream of wheat has two main functions;

1) To provide enough "back pressure" (I believe this the term) to cause the primer to ignite the powder. I have reloaded lead ball for my 410 and on the non crimped or sealed shells, there was no ignition of the powder. The primer went off and just pushed everything out - pain in the ar*e to clean, but lesson learnt!

2) The CoW also provides a phyical mass to push the case walls out. So without it, you might get a small amount fireforming, but I doubt it.

Like I said, I'm no expert and if I'm wrong, hopefully someone can give you a definative answer.

[wildrover77]

I have trimmed thse cases to 70mm, annealed and am using publised loads of powder with pistol primers.

I am just deviateing from the norm by packing the cases with paper rather than cream of wheat.

I was just slightly worried about the safety of using tissue paper rather than cream of wheat.

I am also wondering if I should try to get a pump or double to do the forming with rather than a semi

[Ovenpaa]

A bolt action would be my choice for fire forming.

[Chapuis]

I,m just a bit curious as I shoot 9.3x74r, isn't this a rather expensive way of forming .410 brass cases?

9.3x74r isn't exactly popular in the U.K. and cases are normally very expensive to buy. Have you purchased them via e-gun for instance which is far more reasonable but still not cheap ?

[wildrover77]

I purchased my brass from www.shooting-supplies.eu

Very reasonable

[Chapuis]

Very reasonable - yes it cerainly is. Thanks for the link wildrover77, I can see me ordering a few cases from them and possibly a few other things in the next few days.