Fireforming brass - any reason NOT to use a different powder?

[GetReal]

So fireforming some 6 Dasher for F-class comps. Don't wanna burn up my Varget on fireforming.

Any reason to NOT use H4350 (which I got 3 lbs of and no use for) since I got outta 6.5CM?

to be clear, by "fireforming" I mean not from one caliber to another, but to expand my brass to chamber length and then bump the shoulder back 2 thou.

MY rifle builder recommended this.

TiA

 

[Greenmoustache]

I’m also curious about this, I loaded up a batch of Lapua BR to fireform this weekend into Dasher using 30gr AA4064 vs. 28gr Varget as my Varget stash is running very thin.

Edit - AA4064 worked just fine, did 20 to measure blow length and came out all within ~1-1.5 thousandths. I’m using 108s since I don’t want to waste my Berger 105s but no false shoulder just jammed .030” into the lands.

 

[GetReal]

Edit - AA4064 worked just fine, did 20 to measure blow length and came out all within ~1-1.5 thousandths. I’m using 108s since I don’t want to waste my Berger 105s but no false shoulder just jammed .030” into the lands.

"blow length"? Not familar with that term. Explain? Thanx.

 

[KnowNothing256]

No reason at all, go for it.

 

[spife7980]

"blow length"? Not familar with that term. Explain? Thanx.

When you form dasher from br brass the neck shoulder junction moves forward and the shoulder goes from 30 to 40 degrees so the shoulder “blows” forward on firing.
Length meaning a)where the shoulders measure and then b) the over all length meaning the shorter the neck length the less it stretched in the body.

 

[MarshallDodge]

So fireforming some 6 Dasher for F-class comps. Don't wanna burn up my Varget on fireforming.

Any reason to NOT use H4350 (which I got 3 lbs of and no use for) since I got outta 6.5CM?

to be clear, by "fireforming" I mean not from one caliber to another, but to expand my brass to chamber length and then bump the shoulder back 2 thou.

MY rifle builder recommended this.

TiA

H4350 is just as precious as Varget right now. You could sell it and buy a cheap ball powder like 6.5 Staball to use for fireforming.

 

[Jcarpenter223]

Ive thought about this too on some new lapua brass.

Not meant to hijack but could one not figure the measurements of their chamber based off another case fire formed . Example was i have some hornady white tail. Shoot, measure and thats my chamber. Also to add i have some 1x fired lapua coming in. So theoretically i could take the measurements off my hornady in my chamber and bump the lapua 1x back to match the hornady?

 

[Feniks Technologies]

This is unsolicited advice so I apologize.

But unless you’re in a position where you need every advantage to win a match, and it’s an important match…..

I’d just fireform at a match. Especially if it’s a mid range. Use the 4350 or the varget.

Generally speaking, only the very best shooters will be able to exploit virgin vs fired. And at 600yds, even then, it might not be of consequence. Likely not worth an extra range trip.

 

[Rocketmandb]

H4350 is just as precious as Varget right now. You could sell it and buy a cheap ball powder like 6.5 Staball to use for fireforming.

Or use the Cream of Wheat method and save bullets, primers (you can use pistol) and valuable powder.

 

[Kentucreed6]

Or use the Cream of Wheat method and save bullets, primers (you can use pistol) and valuable powder.

I’m 99% sure you still need a primer and powder unless you have some special cream of wheat.

 

[Rocketmandb]

I’m 99% sure you still need a primer and powder unless you have some special cream of wheat.

Yes - please read my post again:

- "you can use pistol" primers - which are much more obtainable than rifle primers
- and you can save "valuable powder" - in other words, whatever you can find that's sufficiently fast burning and available (pistol again?)

 

[GetReal]

This is unsolicited advice so I apologize.

But unless you’re in a position where you need every advantage to win a match, and it’s an important match…..

I’d just fireform at a match. Especially if it’s a mid range. Use the 4350 or the varget.

Generally speaking, only the very best shooters will be able to exploit virgin vs fired. And at 600yds, even then, it might not be of consequence. Likely not worth an extra range trip.

That's fair. The guy who recommended separate fireforming has more match trophies than I've taken sh!ts in my 54 years.

My Peterson Dasher brass stretches about 12-14/000ths in this chamber. So I figgered ....

 

[Feniks Technologies]

That's fair. The guy who recommended separate fireforming has more match trophies than I've taken sh!ts in my 54 years.

My Peterson Dasher brass stretches about 12-14/000ths in this chamber. So I figgered ....

That’s quite a bit of growth.

But I’d test it, see if you can shoot the difference.

A lot of what is recommended by the best is because they have the gear and skill to exploit it. You may or may not. If you do/can, go for it. If not, it’s a waste of time until you get to the point you can exploit it.

 

[cas6969]

Other than that you're "wasting" powder that other people would kill for? lol