OzFclass

Hi All,
Can this be done sucessfully after fireforming?
If so what is the best method?

Definitely, I always like to turn necks initially after 2 good firings anyway. Majority don't bother with that.

The cases need to be FLS with a FLS die that is not a bushing style. The necks then needs to be expanded using an expander mandrel that suits your neck turning mandrel. If the cases have donut issues like the Lapua .284, then I prefer to cycle the expander a few times on each case to encourage the donut to the O.D. All of the cases need to be trimmed to length, the mouth should be chamfered and de-burred and then the neck turning process can begin.

Hi Dennis,
Thanks for the reply.
I will give it a go.

Hi Tim , also might mention that it can be dangerous if u take too much of the neck eg 3 thou max clearance between neck chamber and neck case .
For a no turn neck all u are looking for is to take no more than 80% of the neck. So u can still see 20-40% of the dull original brass. A tight neck is near rocket science to work out and usually looking for a clearance .0005 thou clearance .
I haven't seen any advantage for a tight neck chamber yet ! But that's another debate !

Back on topic . The theory behind doing it on a no turn neck is
1 helps minimise neck runout .
2. Makes the neck even thickness around the circumference . Thus giving even expansion after ignition . Thus not yawning the projectile and keeping it straight . Also clean the soot of the outside of ur necks with scotch brite .
As this tiny little bit of soot is enough to induce huge neck run out and kill any accuracy u did have .
There are other tricks which I can't give out as it just gives me the edge on my competition . Give u a hint , primer porting that improves standard deviations . If u have a good load , it will improve ur extreme spreads . Looks like it worked for one of my good mates. ( you know who u are!😉 lol)
GS .