No point in starting another thread on this subject, so I thought I'd post it here. There are no videos on YouTube showing the loading and operation of an Anschutz 525 rifle in detail, but this one about a French-made Gevarm .22 is the nearest I could find, and being fairly similar to the former is quite informative. The main difference is with the type of firing pin, which in the Anschutz causes the primer to ignite by a single strike to a point on the edge of the brass casing's flange, whereas with a Gevarm the pin hits the casing's base across the whole of its diameter. Also, the Gevarm doesn't have a deflector plate to force the ejected casing forward... VIDEO
The issues relative to loading are:
1) Sheila would have had evidence on her hand had she loaded the bullets
2) She would have exclusively used the kitchen supply not some bullets from that supply and additional bullets from the closet thus there would not have been 30 bullets remaining
3) She would not have known about the need to manually feed the first round into the chamber by working the bolt. This would have given someone the ability to safely disarm her even if she had inserted a magazine.
Manson disciple Lynette Fromme tried to kill US President Ford but she failed to manually chamber a round so when she pulled the trigger nothing happened and then she was safely disarmed. Her experience was with shotguns and other common "farm weapons" not semi-autos so she had no idea you needed to manually chamber the first round. It sounds bad but Ford was a lousy president so I think we would have been better off had she been successful.