220 Russian fire formed to 6mm ARC

[mkihne]

Sorry getting a bit impatient waiting on a barrel for  the CZ 527 bolt action. Like doing this kind of thing converting 220 Russian by fire forming to 6mm arc. Primary question I am looking at is what to plan for when fire forming. Does the case over all length OAL become somewhat shorter when blowing out & establishing the new shoulder?

 IF so how much change in the OAL shall I plan for when fireforming? May see the new barrel in the coming 5 weeks though I am prepared for more like 9 weeks.

If a Savage bolt action was available I think I may pick one up just for fire forming & who knows I may even like it.

You could expand to 6mm and use a longer bullet to provide a jam. This should fireform nicely(I have formed 6ppc this way.) You could create a false shoulder by first sizing to 6.5,maybe in stages, then size to 6mm until you get a slight “crush” fit for the case. A false shoulder can also be formed by neck turning but only useful if chamber neck is smaller than SAMMI.