I need some help here how much pistol powder should I use to fireform cases 10 or 15 grs of bullseye. It has been so long since I fireformed cases I forgot how much powder to use to get the case to form. I know if you don't use enough nothing will happen.

John

Well I often forget the same thing. I usually start a little light and increase the powder until I get a nice formed case. Then write it down in a safe place to lose later.

I shot some AA#2 and cornmeal in '06 cases several years back to turn them into 7.65 X 53 Mauser cases. After running them into the 7.65 FL die and trimming to 2.100", used LR primer and 10 grains of AA #2 (Bullseye rough equivalent...). Filled the case to base of neck with cornmeal, plugged the case mouth with toilet tissue, took them out into the garage and popped them. Worked just fine...

IIRC, for my 6.5 Gibbs I use 11 grains of Unique, LR primer, fill the case with Cream of Wheat and shove a little rolled up TP in the case mouth.

They are loud when they go off, so I have to shoot them at a gravel pit outside of town.

Cheers,
Canuck

I have a 270 Gibbs. I first form a false shoulder by necking the case up to 338 caliber to headspace the case correctly. I use a large Pistol primer, 16 grains of Bullseye, , 1/4 sheet of toilet paper on top of the powder and fill the case to about 1/4 inch from the top and plug it with canning wax.

I have never lost a case forming this way. They do have slightly rounded shoulders but you can use full loads and they form completely on the first firing.

Do NOT use this method if you have a muzzle brake on the gun!!!

Thanks guys, I will do this, this weekend. Hopefully at the gun show they will have some dies I lucked out last time and found some 25 Gibbs dies for my friend. If not I will have to buy some new ones

quote:

I have a 270 Gibbs. I first form a false shoulder by necking the case up to 338 caliber to headspace the case correctly.

Wow. That's quite a ways to neck up. I bet it works pretty well though.

I use 270 brass and just necking it down to 6.5 gives me a sufficient false shoulder for headspacing.

I have not lost a case this way yet either, and I have formed about 150 cases this way. I get great case life with my Gibbs too. 150 cases has lasted me 7 years!

Cheers,
Canuck

I used to neck up my cases to 30 cal with different 30 caliber dies but I was getting uneven neck lengths that way. I found an RCBS 2 step expander die to 338 works great and is easier on the brass and gives very even length necks. It really does give a very nice false shoulder to the case. I originally got it for a 338/284 Savage 99 that I am having built for close quarters elk hunting but it also works well for the Gibbs