street, first understand, the col in manuals means almost nothing to most loaders, your pressure level is determined by your chamber size and throat length, pressure starts to build once the case is formed to your chamber and the bullet hits the lands

what I do is stick a bullet in the chamber and hold it against the lands with a pencil, then slide a ramrod down the barrel till I feel it touch the bullet tip (ramrod has to have a flat jag on it) I put a mark on the rod, then I close the bolt, run the rod down till its against the boltface, put another mark on the rod, measure the distance between the marks, that's my max col with THAT bullet, you may have to shorten it to max.mag length unless you are happy loading one cartridge at a time
that's how I've done it for 40 years, back then there weren't these tools available, worked then, works now not fixin what ain't broke
RR