My mate who is an RFD is often told that people owned BSA Meteors that could penetrate right through a telegraph pole ! I still have the special heavy pellets that came with the old Career 707 pcp that produced 80 ft.lb. Ordinary pellets were absolutely useless in them. In my early days of reloading I tried cast lead/antimony bullet heads in my .222 to save money, but at 3200 fps they ended up as specks of dust on a target close by.
Baz