Then we are at an impasse Adam. Neither of us appear to be able to prove it either way?
No but there is an obvious answer to Adam's question of why Jeremy made a big deal of leaving the rifle out.
1) In the middle of a rage it is hard to believe that Sheila would go seek out a gun she had a history or throwing things or grabbing pots and pans (which happens to be the weapon of choice for women and while some mock this a frying pan can be a potent weapon)
2) the rifle would normally have been found with the scope and suppressor attached, indeed Nevill had the scope installed professionally and didn't take it off because there was no reason to do so. With the exception of shooting at extremely close range the scope would be beneficial and they did not use the rifle for extremely close range shooting. Likewise the suppressor would be beneficial.
3) the magazine would have been empty and needed to have been loaded.
4) she needed to reload the magazine several times.
It is hard to believe Sheila would go seek out a gun period in the middle of a rage let alone have the ability to successfully load it without someone stopping her before she could load it because she would need to first load the magazine and have to set the gun down so it could be taken away. But if she had sought it ou to load she would not have bothered taking off the scope and suppressor.
Jeremy made up the story to pretend that the gun was a weapon of opportunity that was staring her in the face, made up that the magazine was already loaded so that she didn't need to load the magazine and thus could have rapidly loaded the gun by simply inserting the magazine and chambering a round instead of having to load a magazine and thus provide the opportunity to be disarmed. Finally, it was so that he could claim the gun already lacked the suppressor and scope and thus that is how she would have found it.
To deal with the need to reload he claimed he left near the gun a box of ammo that had been full or nearly full and that he loaded the magazine from it. So it had 48-50 rounds and counting the 10 in the magazine another 38-40 remained for her to reload from. This provided an excuse to make it easy for her to reload. But the staging fell short as the box he staged had 30 rounds. If it actually had 48-50 then it should have had 23-25 remaining after the murders. It had 30 though- too many. So either the box was just staged there an dnot used at all or some bullets were used from this pile and others from a different source which makes no sense at all so this actually hurt a lot instead of helping.
Worrying about a locked closet that she would not be able to find a key to had nothing at all to do with why he claimed what he did about leaving the weapon out with bullets and a loaded magazine nearby.
Adam missed the boat on this one.