FWIW....
for many years I made my own spreaders out of the sides of waxed milk cartons ala' BP's X-Stream design. They worked well and were always good for at least a 10% expansion in the tighter chokes, sometimes a bit more.
I've also patterned a bunch with the Poly-T device that Mike uses but can avoid that weak core by adding a small step in my loading procedure. Say that I want a 7/8 oz. spreader load using the Poly-T device.....then I'll set up with a 3/4 oz. charge bar for the main drop....insert the Poly-T device.... and then add the remaining 1/8 oz. via a small scoop made out of a .38 shell casing. Once the scoop is cut and deburred to a height that holds 1/8th oz., it's pretty easy to load at a similar speed. This can be done with any charge weight, just as long as you save 1/8th oz. of it to go atop the device.
The extra 1/8th of shot atop the disc eliminates any thin areas in the core, and if you doubt it, I suggest you take it to the patterning plate as you'll be pleasantly surprised. One-eighth oz. of shot in a 16 or 12 ga. virtually covers the top of the disc to a uniform depth of one pellet. So, it basically comes down to how big a hurry you are in when reloading. Sorry I've no comparable photos to illustrate this, but there it is......
Rob Harris
