That would be nice, I pour out the sand on a tarp wet it and shuffle it around until it is mixed a muller is definitely in the cards, ironman on YouTube has a good video on his he used a microwave timer to set his.
center (re) drills work well if you only drill the little hole, but tnot the 60 degree part. Even professional machinists get that wrong. A centre (er) drill is primarily meant for drilling for a 60 degree center... when you use it for a 118 degree drill, your contact area is on an edge, and if your flutes are a little out, it will pull the drill out of line. Sometimw waaay out of line. Using a 118 degree spotter drill for a 118 degree drill is ideal.
Center drills work fine. If I remember my schooling correctly the spotting hole should only be slightly larger in diameter than the chisel tip on the drill bit you intend to use. That way it traps the drill point just enough to get the lips cutting. As noted a proper spotting drill would be ideal but then again the budget comes into play! The center drill can do double duty.
I borrowed a buddies drill press to drill a bunch of holes in aluminum angle. I don’t have a drill press vise or fancy riser blocks, so I made up a couple pairs of riser blocks from what I could find in the shop