Personally, I'd get a .280 Ackley body die from Redding and use a .284 Winchester bushing neck die then use the Ackley seating die.
I will assume no one forms bottle neck cases to straight wall cases and no one has ever heard of cylinder brass. Then there is annealing; I suggest a reloader that is a case former use new brass but it seems they always have a pile of brass they want to use up.
I have formed Gibbs cases, for most it is a problem but the Gibbs case shoulder is ahead of the 30/06 shoulder by .034". I have a 30 Gibbs sizing die meaning I can sized a straight wall case or a straight wall cylinder case case to 30 Gibbs to get the shoulder where I want it.
I also fire form cases for the Gibbs chambers. Reloaders believe they can move the shoulder of the case forward and they believe they can move a shoulder back by bumping

. I find it most difficult to move a shoulder forward 'AND' that is the reason I ask about forming straight wall cases and cylinder brass. All the reloader needs to know is where the shoulder is located on the case or the length of the chamber from the shoulder to the bolt face. I form first and then fire.
Back to fire forming. I suggest the reloader use new cases; I suggest using 30/06 cases (and 270 W or 280 Remington cases as an alternative). I suggest necking the 30/06 case down to 7MM and again the reloader needs to know the length of the chamber from the shoulder to the bolt face. After necking the case down and creating a shoulder on the case seat a primer, add powder and then seat a bullet.
Because of the problem with the shoulder on the case the case will have to be fire formed. I form cases once, I do not use toilet paper, Wheaties Gritts or Cheerios, I load the case with what some call 'risky stuff', that normally comes from those that have no clue what happens after the trigger is pulled.
It gets complicated when the case shortens during the necking up and fire forming process. Most of my 30 Gibbs cases shorten .045". That is the reason I say the 270 and 280 case should be an option because the shoulder on the 280 Remington is ahead of the 30/06 shoulder by .051" and the case is .041" longer than the 30/06 case.
The 270 Winchester case is the same length as the 280 Remington case with the shoulder length from the shoulder to the case head the same as the 30/06. I know; that makes no sense but I want all the bullet hold I can get and there are not many cases with shorter necks than the Gibbs case, the Gibbs neck is close to .215" to .217" long. And then I always mention there are many reloaders that think the 300 Win Mag neck is too short at about .264", the 30 Gibbs is .049 shorter.
And we all know I can not increase neck tension I go for all the bullet hold I can get.
F. Guffey