Hey 119er,
Back in December of 2011 I wrote a post on this thread that described what I did when I moved to our new house in 2005. I had about ten presses (six shotshell and four or five metallic) mounted on a very big bench at our old house, and I simply did not have the room to have that many presses mounted at the new house.
Over nearly 50 years of reloading by 2005, I had made a lot of reloading benches at numerous houses. With our new house in 2005, my new bench was only 12 feet long, and I decided to try a new idea of only mounting two presses at any one time, but I would make it so the presses could be switched out very quickly and easily while still being mounted on a rock solid platform. The remaining presses that were not in use were stored closely together on a shelf on the side wall. This allowed much more work room on the 12 foot bench with only two presses mounted at any one time.
The key to having two quick change press mounts was two pieces of half inch steel plate, each 12" deep and 16" wide. After bolting each plate securely to the bench about 4 feet apart, I now had two rock solid steel platforms to mount all my presses. I set each press on the steel plate, marked the center of each press mounting hole with a felt tip pen, then drilled and tapped each of the holes. I drilled completely through the steel and the wood bench to make the tapping easier for the cutting to fall through.
For presses with only two mounting holes like the RockChucker, I tapped holes for 3/8" bolts. For presses using four mounting holes like my Hornady 366s and MEC single stages, I used smaller 1/4" bolts. In the face of a wood shelf in front of each steel plate, I drilled appropriate holes and store the different sized bolts for the different sized holes in the plates.
I can put a press on a steel plate, get the appropriate sized bolts from the shelf face behind the press, screw them into the plate, and tighten them with a socket wrench I keep there all the time. When wanting to change a press out, I take the bolts out, put the press back on the storage shelf, and install the next press.
I can assure you the 1/2 inch steel plate over a solid reloading bench makes any press rock solid - especially when it is secured with steel bolts directly into the steel plate. I do use a flat washer between bolt hex heads and the press body. It only takes a few minutes to switch presses on the steel plates, and there is no need for adapter plates for each press.
Using half inch steel plates that you custom drilled and tapped for you presses is far more solid than the aluminum units sold commercially, and it is a lot less expensive. You just have to spend a little time drilling and tapping your holes exactly where you require them.
In response to Photosaurus, no, the bench does not flex. I make really heavy duty benches, and the steel plates make for a super solid bench which you really need if you are using progressive presses.
As I noted earlier, I just made these steel plates and the new bench when we made our "downsizing" move in 2005, and I figured that would be my last bench. Wrong! We downsized again this year when we bought a townhouse with no basement and no stairs to go up and down. Once again I built another reloading bench which I hope will be my last. While the bench stayed in the last house, the steel plates came along with me to be used on the bench in the new house. Where does one make a reloading bench in a townhouse? First it is a fairly big townhouse at about 1,700 square feet of non-garage living space, and it does have a two-car garage that is big enough to build a bench on my side of the garage. Yes, we still have enough room to keep both cars inside.
I would recommend using the steel plates for anyone. They really are rock solid, simple to make, and less expensive than other more complex commercial systems. You just need to drill and tap your mounting holes, and that is not really hard to do.
Best wishes,
Dave Wile