PLEASE! WHAT BRAND ARE THESE MYSTERY BULLETS?
The drawing you send looks a lot like the Linebaugh (?) WFN (wide flat nose) hunting bullet, normally cast of VERY hard lead and tempered as well. Maybe someone's forming these bullets with moderately hard lead in a thick jacket or something. But, those bullets are usually much heavier than usual for the caliber--Like, 310 gr. for .44 and 330 for .45.
A brand, huh? Pretty please. Some of the staff here have some contacts in the industry and might be able to obtain some modest enlightenment, to the benefit of us all.
Best,
Johnny