I tried all sorts of methods and the best for going from you 30 cal down to 7mm is just necking down the case but not all the way down to the shoulder / neck junction. If a donut ring is left at the base of the neck the case will be tightly held between the bolt face and donut. Just screw the die down a little at a time until the right point is found where cases chamber with a little bit of resistance on the bolt. Remember, with a push feed action the plunger ejector is pushing the case hard forward. If it is short in the chamber most of the stretch will occur at the web and can mean a case head separation - I know this from personal experience
So just load a normal (not hot) load in the trimmed and neck sized cases and shoot. In my 2506 AI a forming load is doing 3000 fps and a full power load is at 3250 so using the forming loads for hunting I dont see a difference
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