Jack,
You can, and I would, leave the Mec exactly as it sits. I'd highly recommend a scale, preferably digital, to measure both shot and powder. Steel loads are both touchier about exact measurements and neither shot nor powder meter well in my experience. I consider loading steel shotshells to be very much like metallic reloading. Use the Mec for size/deprime, repriming and crimping. If you've not looked into procedures, take a look at Ballistic Products website and buy a "Status of Steel" handbook. A good read that will answer lots of questions and includes hundreds of loads to meet most any need.
A piece of good advice, read the handbook BEFORE you load up on supplies!
Steve
