Try to keep in mind these guns were built long before the invention of the plastic shot cup. Their chokes and pattern performance was done when the entire length of the shot column was in direct contact with the bore. Most of them still shot very tight. If you are concerned about the filler wad raising a portion of the shot column above the shot cup of the wad you are over thinking the process. Load the shell with the shot on top of the filler and you will see the choke performance as the gun was designed. Put the filler wad on top of the shot and you have created a poor man's spreader load.

I am with Paul on the Fiber Cushion Wad split in half and loading the plastic wad first then adding the fiber wad as a 2nd step.

With 1/2 inch Fiber wads you can adjust the stack height to suit your load. If using a Mec 600 set the wad pressure to compress it some. They have some spring to them, if the stack height is just a bit too high, shot over the wad edge, they will compress some on crimping. Shell is fired they compress even more so no shot touches the barrel.

I have a 10 load that uses 2/3 of a 1/2 inch 16 G fiber. Take all the 1/3 remainders pair them up and load them just like they were a full 2/3 cut.

Over shot for spreaders I use a Polywad 12 G spreader disk, yellow one with the post. It loads and spreads very well in the 10 G shell.

William

I've loaded Remington, Federal, and Winchester 10ga hulls all the same. I believe they're all straight walled hulls and load and crimp the same. I don't make any changes to the press.

Same here just loaded 100'Remingtons 100 Cheddites, no change to anything powder wad shot filler wad or press adjustment.

Shot almost all of them today you can't tell one from the other recoil report or how they break targets.

William