Bill Lose, Rick Tunell, and I looked on once when Bruce Bannister did one of his "production casting" sessions at his home just outside Winnemucca. We had been "snowed out" from a trip north on U.S. 95 to varmint-hunt, which should be instructive to onlookers as to prevailing conditions that make such a speed-casting method viable. Not a thing for warm weather or an indolent nature (like my own) when pouring bullets. He used a wetted orange shop towel, IIRC, as a heat sink to enable the accelerated pace, touching both mould base and sprue plate extension as needed--which was most casts. Using a Lyman 4-cavity 44 caliber mould, he could make a PILE OF BULLETS in one short hurry. That wet towel sizzled!
Bruce B was a fine man and a great friend. I learned a great deal from him, both what TO DO and NOT DO. It is very likely that Bruce's lessons have enabled me to remain alive and active today. I miss him greatly.
I have used synthetic 2-stroke oil a bit on block tops and sprue pivots to prevent galling. To prevent sprue metal "wiping", I wait until the sprue puddle "freezes", give it a 3-second delay, and cut the sprue with a leather-gloved hand. I seldom have to resort to the rawhide mallet to cut sprues.