I know one guy that anneals his bullets to make them softer so they will expand better at long distances. I knew another guy that pulled the plastic tip out of the ballistic tips to get them to expand quicker.
Some guys just love to tinker.
I made my own bullets for benchrest competition for years. You could control the size of the HP by just screwing the point up die up and down, just like you do a full length sizer. You could also use various hardness of lead core, pure lead, lead with 5% tin in it to help control the boat tail from collapsing during obturation. It was fun to play and see how the HP changed expansion characteristics on Coyotes, p. dogs, and jack rabbits.
22 Rim fire jackets added a whole new world on bullet expansion, Sierra jackets seemed to be tougher, and the J4 jackets were tapered where they were very thin toward the HP.''
Memtb, if you think that altering factory bullets is wierd, how about the guys that are blending powders? WOW!
Same here. I've been hand swaging rifle and pistol bullets for many decades, and I have experimented with numerous styles, weights, core/jacket materials, points, etc. Some gave little benefits over commercial bullets, and some were much superior. I could tailor a bullet style/weight to a specific rifle/handgun/load or for a specific intended game or varmints.
Also, I have played with various old style bullets in attempts to improve performance for a specific task. Today and when they can be found, there are far more options and better bullet technologies than many years ago, so while I do not change commercial bullets much anymore, I do modify a few for specific tasks, i.e. Turn pistol SP's into HP's or sharper points to increase BC, tip un-tipped bullets, modify 22LR's RN into FN for small game, open VLD tips into small HP's, etc.
As for powders, creating duplex and triplex loads is a very old reloading experiment, and while it is for the very advanced reloader that I have experimented and had "some" success with, one does not see it used much today. Nor are there many benefits with modern propellants.
Today with shortages, I would expect some people would take available bullets and attempt to tailor those for another purpose. As our society, economies and shortages change, these things will become more common in the future. Finding or creating a replacement for what we cannot find or too high a cost.