BTSniper 22 cal swage die package offer
I seem to remember ammmosmith did a video on this. It helps to promote core fragmentation. I think #6 is a little large. I imagine 8 or 9 was he used. When I use my RCE dies to FMJ's, I would put 6 pellets of 9 shot in the nose and put my core in, it would give the nose more strength to prevent nose deformation, when I formed the point.
BTSniper 22 cal swage die package offer
I have used bird shot many times. Good results with what I use.
I use pure lead 8 shot without graphite and have no problems. The cores hold together fine and accuracy is on par with most rounds that I used to buy. I use a graphite coating when I want serious fragmentation on target. Very similar to the old Blaser round that they sold in packs of 5 and charged out the ying yang. And I now only use graphite coating in pistol bullets just for that reason.