Projectile seating: It is not at all necessary to crimp for the 7.5 Swiss rifles. Crimping introduces a variable that you don't need. The grip of the case mouth on the bullet will not be identical every single time, thus, the unwanted variable.
To determine proper seat depth for any given projectile, keep in mind that the measurement is only valid when the contact of the bullet's ogive and the lands/grooves is determined. Your manual says OAL is 3.020?... maybe for THAT bullet that THEY used, but ONLY for that bullet profile, not all others. Projectile profiles vary from mfg to mfg. So how do you do it?
There are any number of ways, but I've always used the same methodology. Take a sized, empty and UNprimed case, start a bullet into the case mouth leaving it protruding further than is apparently correct. Place it in the rifle's chamber by hand, ease the bolt into full battery and "smartly" eject it. Meassure that OAL and seat it 2 to 4 thousandths deeper. This is a good start. Later, when you've become more deeply involved in data gathering, you may want to play with seat depths to find the sweet spot for your cartridge. I have specifics I use regularly. Yes, there are other ways. If you like your way better .......use it.
Once you determine your OAL for THAT bullet, screw your seating die down until the mouth of an empty case stops the descent and back it out a full turn. Lock the die in place and back out the seater. Now insert case with a bullet into the shellholder and run it all the way up. Turn the seater down till it touches the tip of the projectile. Keep running it up, turning the seater down and measuring until you've reached your previously recorded OAL for that bullet. Do it a few times to assure that it's consistent. Once you're satisfied, lock it in place.