I did much the same as a student. I had to do absolute density measurements as I varied various parameters. I had a room set aside for it and when I went out I switched on a 100W lamp to compensate for the heat I emitted while I wasn't there (and when I was I sat several feet away while the Oertling settled).
Which is why the idea of using 'standard' pellets came to mind. I think this was required at the Worlds in Germany? I would think it would make for an interesting set of data to have folk put their own pellet through the BFTA chrono (which is the one that counts) and also record the speed with a 'standard' one for analysis. Get some real data rather than thought experiments. Although I was very good at 'thought experiments' instead of doing them for real - according to my supervisor.