Speaking of gas checks, could you use a 22 gas check as a 17 PB for this bullet? A 22 gc is .214 or thereabouts leaving .042 as excess giving a wraparound the bullet of .021 all around. Looking at the bullet drawing it seems like it might work, if you use a thin enough material. Copper foil or soda cans are my first thoughts.
Anyone else have any comments on how this is running? I realize it is not exactly a run of the mill bullet, but I’d like more opinions before I jump into one.