It is possible Sheila was shot first. While sleeping.
Bamber moving her later on, changing the bed clothes & disposing of the bloodied ones.
This would mean he only went upstairs with 10 bullets. As only 9 bullets were fired in the main bedroom. I don't believe he would intially shoot Sheila twice.
Too complicated.
Doesn't seem to fit the pathological evidence of very limited movement between the two shots.
Did he also move the casing? What did he do with the bedding?
Mrs Bamber received 6 gunshot wounds in the first round (2 gunshot wounds in the second round) and Mr Bamber 4 gunshot wounds in the first round all of which were upstairs. Bamber had a pocket full of ammunition and was totally familiar with the rifle so reloading would take seconds.
The ten shots fired in the first round upstairs aligns with how Bamber said he left the rifle/magazine ie to capacity (10) but removed the cartridge from the breech.