Fire forming 6mm Dasher from 6mmBR brass

[Korkt]

One for the brain trust,

If anyone's done it, was fire forming 6mm Dasher cases from 6mmBR brass just a matter of load and fire?

I've read one report saying you should over trim the neck of the 6BR before firing but I can't see why you would when you're just raising the shoulder.

Cheers.

[Chronos]

Yeah I can't see why you'd trim first, the dasher case is .0002" longer so you should be a like to fireform then check length and trim is necessary. It may shorten the neck during forming anyway.

Make sure you use a heavy enough load to fully form the case on the first firing

Chronos

[SendIt]

I think whoever was giving that advice might have confused trimming with turning.

The way I've known it to be done is to turn the neck and stop turning at the appropriate heigh (No idea what this is off the top of my head, you'd need to Google the specs) to create a false shoulder where the soon to be Dasher case shoulder will be.

Then you fire the cartridge and the case expands to form the new shoulder where the turned neck ends.

Eject the case and bingo, 6mm Dasher case formed to spec and ready to load.

[Tiiger]

The way I've known it to be done is to turn the neck and stop turning at the appropriate heigh (No idea what this is off the top of my head, you'd need to Google the specs) to create a false shoulder where the soon to be Dasher case shoulder will be.

Even that's probably not necessary.

If you weren't focused on neck turning already I'd try a few before you run out and guy the gear to do it.

It should be find forming with factory necks.

Just to trial a few at least before dropping your cash on the turning gear.

[Korkt]

I think whoever was giving that advice might have confused trimming with turning.

Could be. Thanks for the info on the turning.

Info on this has been coming up a little thing, not many doing it it seems.

[franc]

Make sure you use unlighted load to fully form the case on the first firing

What loads?

[Lyam]

The way I've known it to be done is to turn the neck and stop turning at the appropriate heigh (No idea what this is off the top of my head, you'd need to Google the specs) to create a false shoulder where the soon to be Dasher case shoulder will be.

Found this Korkt

Fireform 6mm BR brass to 6mm Dasher Brass

[Korkt]

Great, thanks Lyam.

[Chronos]

Make sure you use unlighted load to fully form the case on the first firing

What loads?

Typo, now edited.

Chronos

[franc]

That's making more sense