Ann: Green Niobium-REE Mineralisation Expands, page-29

look out the expert has spoken.

you are great at googling but have probably never seen a drill rig or worked with the samples and data and differences between all the drilling methods.

if you read what I posted I said more shit falling down the drill hole and more dilution and contamination in ac. The diameter of the hole compared to the diameter of the bit and rods is much greater in ac than rc so more room for rubble to fall from above.

ac is first pass, you build resources using rc and diamond.