Bullet bumper, in terms of bullet jacket, or composition of monometal bullets is there a way to measure hardness? If so is there a level of "hardness" you prefer? The Barnes X bullets were "soft" and fouled badly at times like you said. After that some got "harder" and did not expand well. We thought at one time giving them a bit more hollow point might give more reliable expansion. So we chucked them in a lathe and drilled them out a bit. From the same box came those that the copper just peeled easily from, and those we could not cut at all. One of the younger members of the group shot a few deer with them, the "soft" ones had large wound channels the "hard" ones had pass throughs. These were 338 bullets. We "inferred" hardness was the bigger issue than the hollow point. From some of the younger guys Tikkamike, and Riley Barnes may have fixed this issue. The question is if Riley was to experiment with hardness/annealing is there a way to measure it vs backtracking from the results? Thanks for your experience!