In my 32-40's I just chamber the cartridge and with the action open I hold the case in place with my thumb.  Then tip the rifle up about 30 degrees and gently lower it before closing the action.  I can't prove it, but I think it puts the powder in a happy place consistently.  Anyone looking can easily see that the action is open while I'm doing it, and I sure can't set off that primer with my thumb

Chris.