One bullet for Sheila certainly. He must have cringed when he realised another bullet was needed.
One bullet would leave 9/10 bullets left. Did Jeremy think that was enough ? If he did he over estimated the rifle power. Neville got downstairs after receiving four shots, including head shots, and June got out of bed after a head shot while her head was on the pillow.
It may have been possible to kill the twins with one shot each. But if they were shot last, Jeremy would have already fired lots of bullets. So would have no choice but to fire lots of bullets into the twins, to make it look like a crazy killing.
Jeremy having to re load turned out to be a big problem. AE immediately got suspicious. Only believing Sheila had fired 11 bullets because that is what she had been told. When she found out Sheila had re loaded twice she knew she was not guilty.
If if was an 'open & shut' case as Jeremy told Julie it was, the re loads were not a problem. However it soon came to light that there was no evidence on Sheila showing that she had reloaded. Jeremy also eventually back tracked and admitted Sheila had no experience with guns.
Do people believe Jeremy's plan was not to re load, but failed in this plan ? Or believe he did not care or consider whether he would have to re load ?