Well it can be as easy as resize, load and go but it can be a bit more trouble. Whenever sizing down you may end up with a thicker than standard neck wall. This may require neck turning. You can check that by seating a bullet and checking the neck diameter (with bullet in) against the specs in the book. I doubt that you will have to trim the cases but I always check that as one of my steps in preparing the brass. You might need to load less powder than the manuals allow but you would have to check that after fireforming the brass. Just weigh the cases and compare that weight to a "factory" case weight. (the case used in the data you are using) for every 6 grains additional brass weight you will have to reduce the powder charge by 1 grain. If your cartridges weigh an average of 12 grains more than factory cases then you should reduce the powder charge by 2 grains.
