That is quite unbelievable patterning, especially from a subgauge with only 18 grams.
Just importing now 3kg of #7 for fox hunting in my 20 gauge via Alibaba. I haven't reloaded a shotgun in years so when I get some patterns done I will report back here. It cost US$267 including freight but excluding 10% import tax. 20 gauge TSS turkey loads are excess of US$10/shot. I think I can do them for under US$4/shot by repurposing Eley 28gram 20 gauge target loads, wrapping mylar in the wad and roll crimping. I'll see how I get on.