As a contractor, one of my jobs a long time ago was repairing work after the Clean up crew had been in there...(regarding the formation of the first death scene company in the 90's, Service-master has had a division doing way longer than that. Also several other disaster services companies I have worked with did that kind of restoration work.) I was called in to bid on replacing stained wood floors and replacing wall board after several shootings. Most were suicides. but a few were murders. I have no idea if the guys story is true or not, BUT I have seen enough shoot sites to say that yeah, a .357 or larger can blow body debris a long way inside a house. a twelve guage in the mouth will just about paint the ceiling or wall. A 45 auto loaded with ball will pass thru every time.
Now, after doing that for a few years, we got a call to a house where the homeowner had passed away to natural causes the day she was planning to visit her condo in florida. She had canceled her mail, shut off the phone and packed her bags when she broke her hip and died on the floor. No one thought she was home and it took approximately 60 days till a utility worker noticed that she had not paid her bill despite never missing a payment in some 40 years. Cops were dispatched to find her remains lying near the dead phone. We got called in to look at replacing the flooring in the living room which were stained. The smell in the house was unbelievable, despite being cleaned professionally by people trained in that area of restoration, every time the heat would come on, we would get nauseated, After three attempts at cleaning and deodorizing, including one whole house bagging, and fumigation. The insurance company finally decided to have the house razed and rebuilt. The poor womans only relative was a niece in California who had little or no contact with her, she did not go to church and had been retired for nearly 20 years from a large department store. When we had the back hoe and knocked the house down, even then the smell was overpowering