Ann Eaton testified that Jeremy asked her and her husband about buying a five bullet shot gun from them. This was just before the massacre.
The advantages of this is one bullet results in certain death. Whether in the head or torso. So no re loads needed if each bullet hits it target.
It is much more realistic that Neville would be worried about Sheila with a shot gun.
Jeremy would have to justify why his shot gun was at WHF. That would not be hard. As he worked there & it was his family home.
The gun would carry less bullets, so a potential re load if any bullets missed. But he would have time to re load if Neville was out of the way. However if no re loads were needed, that would make it more likely Sheila was the killer. People have always found it hard believing Sheila could re load.
A shot gun is loud. And I am not sure a silencer can fit on one. But if Jeremy is quick and clinical, then people would be dead before fully waking up.
Using the shot gun means there are no rabbit stories. But that has never been believable.
I suspect Jeremy got too short notice about Sheila's visit. So had no time to purchase the gun. Using the rifle instead. Or he may have simply preferred the rifle, preferring the extra bullets, overestimating it's power & having thought up the rabbit story.
Would other people use a shot gun or rifle ?
How is it that you can be here so long and not know that the semi-auto shotgun was dropped in favor of the Anschutz? It had nothing to do with no thaving time to buy it. Neville refused to buy a semi-auto shotgun so he settled for the semi-automatic rifle.
His excuse for wanting the shotgun wa sbecause he wanted to get into game hunting. Quite obviously he had ulterior motives because what person who actually wants to get into game shooting decides to drop it because his father will only allow him to use a double barrel shotgun and not a semi-auto?
He wanted a semi-auto to commit the murders with and his first choice was a shotgun but since his father would not buy that he had to settle for a semi-auto .22 rifle because that is what his father was willing to buy him. There was no further consideration of a semi-auto shotgun after getting the Anschutz.
It might actually have been a good thing getting the rifle instead because it has less recoil so was more credible for Sheila to have used it but the bullets being less potent did cause some problems that would have otherwise been avoided in retrospect. For instance he could have killed Nevill then restored the phone to the bedroom to pretend he made a call from there before being shot. Instead he pretended the call was made in the kitchen then Nevill was shot there but evidence he was shot in the beroom first ruined the staging effort.
Since he only used it a few times for target shooting so he could try to become a decent shot with it in anticipation of the murders, it was in brand new shape still when AP tested it out.