fireforming brass

[Kevin Stenberg]

I have FF 223 to 7TCU but i have forgotten how i did it. And now i need to change some 308 to 358 Win brass.
If i remember correctly I used like 4/5 gr of a fast pistol powder. i filled the remainder of the case with corn starch which was packed lightly to the bottom of the neck. Then I filled the remainder of the neck with TP. And fired the case in the desired chamber.
All of the cases to be changed are already annealed.

 

[Rick]

I've made thousands of 7TCU but never went through all that. Haven't made any 358 though. In the 7TCU I used my standard 4895 load backed off 1 to 1 1/2 gr. No filler needed or wanted. Seat the bullet to engage the lands on lock up so the case head is held firmly against the bolt to assure consistent shoulder placement.

 

[CWLONGSHOT]

Thats how I did it as well. I found a bunch of 175g Corlokts for a song. (Decades ago) a d used them. Bang perfect case removed.

358/308 was cake and FF unnecessary. Run them they the 358 die load and shoot.
CW

 

[RBHarter]

I stepped up the 308/358 one step to 8mm I think , then 358 . I don't recall any issues other than the original odd lots of brass that came with the dies .....

I'd anneal the 223 , go to 6mm or 25 then 7mm anneal again and load something to around 30kpsi to fill them out .

 

[Rick]

Never annealed a single 223 for 7TCU. Lube the inside neck and use only a tapered expander.

 

[JonB]

when I fireform 257rob cases in my 6.5x257r, after I expand the neck, I just load 'em with a standard cast bullet charge and seat a cast bullet and shoot.

 

[CWLONGSHOT]

I also dont and didnt anneal them. BUT when I make my 7.65 Arg and my 6.5/06 I MUST or they WILL split 75+% of the time!!!
I just pulled two boxes of 7.65 I had loaded five years ago with Jacketed. 7 cases where saved.... No, I hadnt annealed those. The reason some calibers REQUIRE it and others seemingly dont is a question to ponder.
Another one is occasionally will anneal but seldom have a split neck or issue is my 300 bo. Humm.

 

[RBHarter]

I formed some HPX 06' to a short shouldered long neck 280 AI . I lost over half in the fire form annealed or not Win , Rem , or FC no problem ..... Like 10 each the barrel was wasted . I made 25 cases 243 to 6.5 Japanese and cow formed them no losses to that point .

I think I'd rather waste a dime in gas than 50¢ in brass .

 

[CWLONGSHOT]

I loose very few in the process as well... But left sitting for a few years and TINK TINK TINK.... most will be cracked or crack upon firing or with sizing...