Grt case modification

[AJC1]

Loading 6x45 for inital shots. I think it should be as simple as just changing the neck diameter of a 223 case to 243, and making an inital run. After inital shoots, measure volume of the case, adjust grt and done.... am I missing anything???

 

[TEXASJD]

Only thing I would really watch is case necks probably going to see some splitting without annealing?

 

[AJC1]

Only thing I would really watch is case necks probably going to see some splitting without annealing?

Apon further playing, there is a case and chamber that requires modification. I need to modify a lot more.