mp 5.52 bc

anyone got a ball park idea of what the bc is of the mp 5.52 slugs is. I cant seem to locate and data on their site or anywhere on the net.

shooting through slug a liner on impact mk2 700mm. anything on the hot side and these things spiral and wobble terribly. sub 900 and they stay fairly stable. still dialing things in and figuring this new to me mold out.

got them in the 850 range currently, but they hold a group for a bit and then scatter and go back. may need to inspect closer. Sizing them down to .217 using NOE sizers. tried .216 but they got worse in group holding. and also worse with .218. they're weighing in at 35.5 with awesome consistency. and all around .421" long