Interesting. Geoff Macdonald says something similar with his "Hydro's" producing less pressure than say his traditional FMJ. As to OSR he believes it comes down to barrel tensile strength not barrel thickness. A mate of mine is a Barnes man and loves the TSX. His last trip to Africa with the 458 Lott loaded with 500 grain TSX's. He shot a buff and all was ok. He then shot a Waterbuck with this load and the bullet didn't open up nor did it exit. My point is if you shoot enough animals all bullets will have anomalies.