Fire forming

HIGHRPM

HIGHRPM

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I need to fire form some brass for my Arisaka Type 38, but I have never done it before. I have read a couple of ways, one with cream of wheat, one with just tissue paper, but nobody really mentions powder charges. I have Reloader, 15, 17, 19, 22, IRC 4350, 4895, 4831 at my disposal. Could someone tell me what is safe to use and what way they do it? As always, thanks for any info, I love learning and this site is the best !
 
what is your parent case going to be?

I would start with 10-12 grains of unique under a full load of cream of wheat held in place with a piece of tissue, if the case doesn't fully form then up the powder a grain at a time until it does. If its a big jump from the parent in the neck/shoulder area you may have to anneal first to avoid splitting the brass
 
Actually I just want to form the brass to the chamber as the chamber is loose and I was told to fire form, to stretch the neck and shoulder out more . The case is original 6.5 Jap, 6.5x51. The cases have been annealed from the factory and are new.
 
If the headspace is so loose that you need to blow the shoulder foreward, you would be better off to expand the neck to, say, .270, then partially neck it back down to 6.5, leaving enough of a false shoulder to hold the casehead against the boltface. Fire a conventional bulleted load. It will shoot well enough, and will fireform nicely. After this first firing, just neck or partially size the cases, to keep the casehead against the bolt.
 
mwjones said:
Load up some normal loads that you would shoot, and shoot them. Neck size after first firing.
Click to expand...

The catch is that if the rifle has badly excessive headspace, the cases could experience incipient separations on first firing, and be useless for reloading.
 
I was told that it might be a headspace issue. I was also told to fire form the cases due to the cases that I fired had a bulge about 1/4 " above the head. That way I would stretch out the shoulder and neck, then the case shouldn't bulge near as much. I have yet to find a maker of 6.5 Jap headspaces gauges to check that part.
 
The bulge 1/4" up from the head is likely the expansion ring where the solid casehead transitions to the case walls.
If so, this is nothing to do with headspace.
 
tiriaq said:
The catch is that if the rifle has badly excessive headspace, the cases could experience incipient separations on first firing, and be useless for reloading.
Click to expand...

Try this old trick: Go to canadian tire and buy a giant tub of o rings. Find the ones that fit tightly when you roll them down over the bullet to the rim. When you chamber them in the gun, it'll be a tight squeeze to close, but will hold the case head back against the bolt face while fiting. From then on, they will headspace off of the new blown out shoulder. It might help, works with .303 :)
 
I will give that a try, Between the orings and the cream of wheat I should get some desired results. Thanks everyone for the advise.
 
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