I have tried attaching all sorts of base wads to slugs and so far have been largely unsuccessful.
Any plastic gas seal/cushion legs I have tried are too fragile. I thought I had a good one with a steel shot wad as it appeared to be pretty similar to the cushion leg on the Gualandi DGS slug but they failed and after shooting comparison with a DGS showed that the DGS cushion leg and gas seal were quite a bit thicker and tougher.
I will be very interested if someone find one that works.
In the mean time, I will be looking for some really heavy felt to try punching out felt wads with screw holes in them for slugs I cast with a central hole for the screw Brenneke style.
I am having another test run of my ribbed hollow base slugs this week. This round has a thickened skirt to resist deformation on firing but I am thinking a solid with attached basewad is the way to go.
By the way Ed, I don't know how you find the time to do so much and post so much information but I am glad you make the time. This is really interesting!
Thanks,
Longbow