Since you have previously accepted the twins were first to go this contradicts your above post.
It's rather ironic that you believe the twins were first to go and that nevilles burn marks were made with the barrel of the gun. Both these point to Shelia being the killer.
Well I agreed that Bamber may have shot one bullet each into the twins, before entering the main bedroom. As he would still have enough bullets left to kill a sleeping Neville and June. However I don't agree with Buddy that the evidence shows the twins were shot first.
This thread is about why Neville called Bamber and the 5th furthest away police station. Rather than ask June for assistance, or why June didn't wake and offer assistance. You have said it is because Sheila had already killed June. You have also previously said the twins were shot first.
Do you believe Sheila was reloading when Neville called Bamber after she had killed June and the twins ?