Also off of Stiletto's site is this 5.1-gram 5.45x39 AP - this goes a slight kick above AP45 and matches their heavy 5.56 AP. 10mm HB550 at 500 meters claimed for both, which IMO seems rather high. It's only slightly inferior to their 7.62x51mm, which claims to pen the same at 550 meters. .338 Norma raises to 16mm HB550 at 550 meters.