When I FL size bottleneck brass that wasn't fired in my rifle, I start just short of the shell holder touching the base of the die. Run a couple through and test chamber them. If they go with just a butterfly sneeze more effort than the bolt by itself (they usually don't), I measure for length. If they're within spec, I run the die in about 1/8 turn and resize both. If they're long, I trim them before that second sizing. Test chamber them again. That usually nets a nice clean closure. If not, repeat the 1/8-turn / test / measure-for-length drill until they chamber to your liking. That diligence may seem anal, but it avoids setting the shoulder back too much, then having the brass get overstretched upon firing. When you have two cases just like you want them, FL size and trim the rest.
After their next firing, I'll neck size and test.
Never load FL sized rifle brass that hasn't been test chambered in the gun in which you will use it. You can guess how I learned that.