I find it is difficult to be a machine.
Having run thousands and thousands of weld beads in all positions on different materials, I’ve internalized the need to vary technique, travel speed, deposition rate, and my angles to end up with a weld that looks the same at both the beginning and the end. In the beginning the base material is cold, you must move slower, so the base material can come up to heat and fuse properly. As you move along the base material is gonna get hotter and hotter. The heat will dissipate out away from the weld area, but eventually the heat in the weld area will build up to an excessive level, at that point you must be moving faster and making technique corrections. Even when you make the beginning and the end look the same, the base material was affected differently along the length of the weld.
There are automated processes like casting machines that can hit a plateau of temperature consistency, both mold and alloy temp. However I suspect that the bullets cast at the beginning of a session, while the temps are stabilizing will be slightly different from the bullets cast during the middle of the session.
When I cast there seems to be three distinct parts.
1. “The ramp up”. It’s a little cold for a bit. Hopefully just three or four wrinkled casts.
2. “The middle stride”, it all settles in and runs well for a bit. Because I don’t use a PID or a thermometer I use the edge of frosty as my temperature guide. I find myself making adjustments to casting cadence based on bullet appearance.
3. “xxxx, it’s time to stop!” This could be the wife calling down that dinner is ready, I let the alloy get to low, my hand hurts, I need to pee, or the sprue plate screw backed out and I don’t have a fastener manipulation tool handy.
Basically what I wanted to say with all this is that I don’t think using a metronome is a bad idea, I think that it would be most helpful during “the middle stride”. If you go down this rabbit hole, you might also try timing your pour cadence with it.
Art & Science! Stroke it how you like it!