Every sane person (me and you ancluded, a63nt 5m1th) would look for minigun sounds in a folder called... well, "minigun".
Unfortunately, R* does not seem to employ any of said "sane" persons, at least in the sound department.
and the one named _SPIN are just that; the beginning, spinning and spin-down sounds.
The actual "BRRRP" I'm looking for ain't in there
By the way, I had the sounds converted to mono already. I'm utilizing Audacity and Wavosaur for all edits
In the meantime, I copied my backup-resident.rpf (but left the weapons_player.rpf) - the minigun was indeed affected
by the resident.rpf, since the sound reverted to the vanilla one.
Started picking apart the resident.rpf gunshot sfx again, I changed other variations of MGN_AK47_PLYR individually -just, they don't turn up anywhere outside OpenIV either