It does not matter how the ammunition was marketed. Both bullets went deep into the brain, the same make and model bullet that killed Sheila instantly via entering her brain.
So I shall again. If June was shot twice in the head whilst in bed, how did she manage to get to the door?
There is no possibility of a woman shot up to seven times while asleep bed, in the head, throat, chest, knee & stomach giving a 'crazy' Sheila scratches. Which is why the pathologist said there was none.
June crawled a few feet. Bamber may have shot her once again when he returned upstairs.