sizing from 17 fireball to 20 vartarg
 

Need some help please on Methods and required dies for sizing up 17 fireball to 20 vartarg.

An expander die. If the shoulder is in a different location, might want to expand them to .224 first, then neck down to .20 Vartarg, forming a false shoulder, for a crush fit.

What He said.

Tom

Yupper......

What they said.

-BCB

AND: IT the necks split.

Take a torch to the necks just long enough you can see

the color start to change.

Then drop in a can to AIR COOL.

They shouldn't split after that.

Don't quench in water! They'll still split if quenched.

Use Imperial Sizing Wax, Hornady makes the same stuff
you can get it from midway, or maybe a local gun store.

Make sure to get a bit on the INSIDE of the case mouth.
It don't take much so don't get carried away with it.

I wouldn't size it up, then back down, that's over working the
brass double what's needed. Just stretch it what's has to be done.

IF you have trouble doing these things, send me a pm and I'll try to
coach you thru it. Simple doings though.

George, I always drop the heated brass into a bucket of water. I have never had a case neck split doing that. They've always been good for many firings after annealing & quenching.

Expanding the case larger, then down to calibre is to establish the false shoulder for proper headspace.
This was mentioned as a solution IF the headspace of the ctgs. was different.

Maybe you missed that.

Brass doesn't have any phase transformations like steel does, so the water quench will just cool the brass quicker. I don't water quench when I anneal, because I do not want to have to dry it all if I need it quickly, just drop it in the pan and let it cool in air.

17 fb
 

Dog hunter
the best would be to trade for 221fb and form to vartarg,17 fb has 30 deg shoulder 221 has 23 deg not worth the work.i form all my vartarg fron 221fb.how many do you have and are they new brass?

What Geogre said fire em then anneal again.

If you have annealed your cases, or have new ones in 17 FB, you can just lube the case neck and slowly run the 17FB directly into your 20 VT sizing die and it will expand the neck to 20 cal.
This is what and how I do some, if I am sizing 17FB into 20vt or 20scc.
Keep it simple. Then load and fireform into your VT chamber. :)