Thread: My 260AI Load Development Begins

The brass is 260 brass the chamber is 260AI. The first firing will blow the shoulder out to fit the chamber.

The other way to do it is to open the neck up to 7mm and then form most of the neck back down to 6.5mm. This way the last part of the neck forms a false shoulder. When chambering the brass there should be a slight resistance. This is what you need to do if using the cream of wheat/fast shotgun powder method to for the brass.