I have the same mould. Nothing untoward will cause concern if you lube a gascheck bullet with a BP compatible lube and just fire away. Leave lube sticking to the shank. This is true for all GC bullets with any powder as long as MV is kept under about 1600 fps. (Hard to get over about 1200fps with BP anyway.)
However; A wad might make for a more successful load. I punch mine out of various materials, milk cartons, pulp egg carton, beer coasters, cereal boxes, tablet backing or whatever. The thickest wad material I have located, free, is backing card from a picture framing shop scrap bin. I sometimes soak all but the milk carton in melted lube. Egg carton material is more porous thus holding a bit more lube. (This is what I use for percussion revolvers.) Wonderwads work, but cost filthy lucre!
My wad punch is a belted magnum case cut off at the shoulder and sharpened with a counter-sink bit. Either drill out the primer pocket to push out the wads, or file/grind a port on the side of the case body.