Anyone ever fireform brass?

[gmar]

I've been reading that I can fireform 7.62x39 brass into 6.5 Grendel brass. I understand the basics:

1. Run the 7.62x39 brass through a 6.5 Grendel sizing die
2. Add the primer, powder and bullet
3. Fire said round and now I have 6.5 Grendel brass.

Has anyone ever fireformed brass before? If so, am I missing anything or is there anything I should look out for? Any tips on how I should start the recipe for the load? Sounds pretty simple but for some reason the idea kind of scares me.

 

[1mathom1]

I cannot answer re: the Grendel round but I have fireformed .357 Herrett brass. Procedure was much as you state above but I have to trim the .30-30 brass back after running it through the Herrett die. The Herrett die forms a shoulder that the Contender headspaces on. For the Herrett, the suggested fireforming load was the minimum load. I have seen other fireforming instructions that warn against going too light though....might not completely form the round. Sorry I cannot help much beyond that re: the Grendel.

 

[Randall]

I have done 30 Herret and 7-30 waters from 30-30,7-30 just run it thru the die and fireform,30 Herret; size,trim,fireform.Neither one was hard to do,I did split a lot of brass tho.Probably because I never annealed any.

 

[HiredHand]

I don't think you can fireform in a semi-auto but you might already know that.

 

[gmar]

I don't think you can fireform in a semi-auto but you might already know that.

From what I've read, people have been doing it for their semi-auto Grendel. Is this a bad idea, if so, why?

 

[GUN DOG]

don't know about a semi auto I just finished up 100 250 savage AI's, 15 gr unique with a wax plug for a bullet. Over sized the neck a few tho so it had to be forced into the chamber & not back out when fired, like a crush fit

 

[HiredHand]

From what I've read, people have been doing it for their semi-auto Grendel. Is this a bad idea, if so, why?[/QUOTE

I think it's because the case is still expanding as the extraction cycle begins. I could be misinformed or this may not be an issue at all.

 

[criticalbass]

The only fireforming I currently do is for my 338-06. Just expand the '06 case mouth to .338, load a .338 bullet, and fire the round. The unexpanded '06 case holds enough powder to shoot pretty well, and the expanded case will hold a few grains more.

It is possible to do it by shooting 30-06 rounds in the gun, but it is wasteful and though it isn't supposed to do damage to the bore, I still don't like to do it.

I have seen information on fireforming by using some sort of wadding to create enough back pressure to form brass with no bullet involvement, but do not recall the details. CB

 

[Blitzfike]

I fireform 357 herret, 30 herret, 6.5 swiss, and form 400 corbon brass from 45acp. The 400 corbon cases do fireform the first time I shoot them, and they are a little shorter than the actual 400 corbon brass, but when I form any brass from another caliber, I adjust the die so that the headspace with the formation of the shoulder is minimum. (sometimes I adjust it so that I have to use a little more force to close the bolt..) That is especially critical in the herret series. I have made 357 sig brass from 40sw in the same manner as making the 400 corbon. If you have any of the so-called Ackley improved chamberings, you usually form the brass by firing the parent caliber in the improved chamber, that blows out the shoulder and gives you the additional case capacity for slower burning powder charges. Don't be afraid to jump in there and do it. If you anneal, you will find that necking down to a smaller caliber, you will destroy more cases than doing the forming without annealing ( you will push the shoulder into the case if you do). If you are expanding the case mouth to a larger caliber, annealing is good before you do the forming. I anneal most of my bottle neck rifle brass after a couple of reloads to extend case life and prevent cracking. Be careful to place the base of the cartridge in water so you don't make the case head soft. A propane torch held to the case neck and shoulder just briefly until the brass slightly changes color is all it takes. Use care not to overheat the brass. Blitzfike

 

[redmax51]

I accidently fireformed a 338 Win Mag out of a 7mm mag.LOL Made the prettiest 338 w/7mm head stamp on it. Steve