Was browsing in the NRA range office at Bisley yesterday and saw some boxes on PPU bullets. Upon closer examination I could see that they were Henry Krank's and the professional packaging proclaimed the contents to be (various calibres of ) "PPU Bullet Heads". I was suspicious of this, thinking that they might be forgeries.

A little interweb searching shows:

The PPU website simply (and correctly) describes them as "Bullets"

The Kranks website makes extensive reference to Bullet Heads.

.......so this would seem to be something originating within Kranks themselves.

Disappointing.