I may not understand the question, but to attempt this: [ QUOTE ]
the bolt gives slight resistance when closing.
[/ QUOTE ] as a function of fireforming is not quite the purpose, unless you are shooting full charge ammo with a bullet, and then bumping the shoulder?
The only thing gained by fireforming is the expansion of case dimensions. Resizing, on the other hand contracts the outer dimensions. It would be very difficult to accomplish both, by a fireforming operation. Additionally, you still need to fire an assembled cartridge in your modified chamber before you have aquired a case that actually "fits" your chamber, and has achieved proper case capacity, to the point where it would benefit by "bumping" the shoulder.
You know when you have used enough powder when the case "looks" similiar to the chamber dimensions, althugh the angles may not be quite as sharp and distinct as if you had used a full power cartridge, in the case (situation) of an Improved cartridge, like an Ackley. It almost always requires a second firing to get the sharp corners....without a bullet.
Now, if this (information) doesn't further confuse you, I'd be surprised. It would be better to take a couple baby steps than try to grasp the whole enchillada.
Another question that comes to mind is why screw with 7Mag cases, when you can buy 257 Weatherby, and omit some tedious procedures?
Good hunting. LB
edit: another thing I would like to comment on. I have used the filler "cream of wheat" several times and it seems that we are overlooking the fact that it is completely unnecessary, and causes more problems than it is worth. You don't need it; and if you use it, you will probably get it in the action and inside the chamber area where it will produce dents when you fire the next shot.
Use a fast pistol powder and rolled up newsprint and point the barrel straight up in the air and if you need more powder, add more powder. On the other hand, metering cream of wheat or weighing it and cleaning it out of your action and chamber is a real (and unnecessary) mess. I have been there and done that and the inert media is a bad idea, regardless of where or how many times you have seen it described in various places. Some information is better than other information. LB