I hate to say I told you so, but I predicted this a while back. Not “you”, but “you all”, anyway. Tungsten and bismuth are both in-demand heavy metals that come almost exclusively from China. Not only are the tariffs driving prices up, but all the other industries using these metals are also driving the price up. It wont get cheaper, thats for darn sure. I see zero reason to move to a subgauge gun that relies on heavier than steel shot for waterfowl hunting. Love me some steel and my 12ga.
Never tried copper. Found an article with mass of copper vs other shot, which indicates:
TSS (18.1 g/cc)
lead (11.34 g/cc),
bismuth (9.8 g/cc),
copper (8.8 g/cc)
steel (7.84 g/cc)
Based on this the copper is better than steel, but really sits squarely between steel and bismuth. Even bismuth is 2 steps worse than regular old lead shot as far as retaining velocity and penetration at distance.
For turkeys I only shoot a shell or three per season, so while TSS is stupid expensive it is easier to justify. But if I had to go back to lead shot it wouldnt really be that big of a deal.