Where's the part about him "dry-firing his rifle" supposed to be?
Mrs. OSWALD. I did not see it, because it was dark, and I would be in the room at that time.
But I did hear the noise from it from time to time not often.It appears to me that the noise she heard was most likely from LHO operating the bolt.
I am pretty sure that you will disagree. If so, what other rifle noise would she be able to hear from inside?