Fireforming load: 6BR-->6Dasher

[earthquake]

What's a good 6BR to 6Dasher fireforming load that's worked for folks?i I have Varget and 4166 on hand.

Jammed 0.030" I've heard, but a friend of mine's FF load is my regular BR load, 30-gr. Probably should back off that, huh?

I'm not doing a false shoulder though. Thanks!

 

[RegionRat]

It still takes 30 to 31 grains (Varget, CCI 450, Lapua) to fireform with either method.
The trick is to start like it is a normal load development and see where the rig does best accuracy wise while fireforming. Some guys have won matches while fireforming.

 

[Shoots 700's]

I jamb .030 and use 30 grains of Varget

 

[earthquake]

We'll alright then, thanks!

 

[earthquake]

Here's another question....

I made a boneheaded move reloading for the GAP Grind this weekend. I grabbed my box of 6BR brass from my safe, ran all 200 pieces through my 6-Dasher FL sizing die and primed them.... thinking it was my Dasher brass! ??‍

Did I ruin them? They are tight now in my BR chamber, but seem to be ok in my Dasher chamber. That's why I figured I should just convert these all to Dasher now by fireforming.

Here's the question: am I overlooking anything that might cause issue/harm to me or the gun?

 

[RegionRat]

I am a little concerned that the Dasher die made the 6BR brass feel tight in a 6BR?

Try and compare one of these sized pieces to a virgin 6BR and see if you can tell why the accidentally sized ones are tight.
I'm a little surprised and wouldn't want to say something is okay when I am not sure what that Dasher die did to the brass.

The Dasher shoulder should be too far forward to affect the 6BR, so lets make sure the necks won't do something funny before we make any assumptions.

 

[Milo 2.5]

Here's another question....

I made a boneheaded move reloading for the GAP Grind this weekend. I grabbed my box of 6BR brass from my safe, ran all 200 pieces through my 6-Dasher FL sizing die and primed them.... thinking it was my Dasher brass! ??‍

Did I ruin them? They are tight now in my BR chamber, but seem to be ok in my Dasher chamber. That's why I figured I should just convert these all to Dasher now by fireforming.

Here's the question: am I overlooking anything that might cause issue/harm to me or the gun?

I looked at case diagrams of BR and Dasher, all things equal, the case body should not be the issue, the Dasher has a slightly larger base, but the BR may have a larger diameter at the shoulder, albeit they are in a different location. Did the die put a goiter on the neck, causing an issue?
Did you try resizing the brass in the BR die to see if chambering improved? It needed sized anyway if you decapped the cases. That would be the true test, if not chambering after that, lol, now you have more Dasher brass than you planned.

 

[shoot4fun]

For the most consistent fire-form to Dasher the best way is by creating a false shoulder in the neck of the BR brass.
I "cheat" when I've done it in the sense that I have a Redding Competition Neck die in 6BR that I use to give my BR brass a slight crush fit in the Dasher chamber of my fire-form barrel. In other words, the bolt will be difficult to close for fire-for rounds. Start by lubing insides of necks (I use Imperial Dry Lube) and then expand them with a .257 expander die. Then go to the neck die and work the neck back down slowly until that crush fit is there. Load them with 30 grains Varget and chose jam or jump (won't matter if the crush fit is there). Of course, if you chamber is tight neck the you need to turn the necks. I usually do this step just before powder, bullet and primers go in.

 

[MBanning]

Here's another question....

I made a boneheaded move reloading for the GAP Grind this weekend. I grabbed my box of 6BR brass from my safe, ran all 200 pieces through my 6-Dasher FL sizing die and primed them.... thinking it was my Dasher brass! ??‍

Did I ruin them? They are tight now in my BR chamber, but seem to be ok in my Dasher chamber. That's why I figured I should just convert these all to Dasher now by fireforming.

Here's the question: am I overlooking anything that might cause issue/harm to me or the gun?

I would be worried about case head separation. Without a false shoulder or a bullet jammed tight in the lands the brass can be stretching near the base. That can be bad.

 

[Campguy308]

Just pick up some of that new Alpha dasher brass