Try reading
study of 653 revolvers, 242 pistols, 181 shotguns, and 124 rifles used in suicides
Absence of blood on or in the barrel does not preclude a close range or contact wound
Try telling that to the Texas Forensic Science Commission that conducted the study
I know how to read but clearly you do not and since you were corrected so many times at this point once is forced to conclude you are intentionally misrepresenting.
Did you miss the part about close range? By definition someone committing suicide by shooting himself/herself is firing the weapon at either close range or contact range because people do not have arms long enough to pull a trigger at intermediate or long range.
The study did not consider only contact wounds but rather simply suicides without regard to whether a contact wound or not, and simply concluded all shots had to be close range or contact range because people do not possess arms as long as plasticman.
http://static.comicvine.com/uploads/original/10/101435/3020845-plastic-man.jpgThe commission conclusion is simplistic and largely useless. All it concludes is that IN GENERAL there can be situations in which blood doesn't get in the barrel though it will get in the barrel a majority of the time.
This simplistic general conclusion doesn't separate contact wounds from close range. Nor does it separate drawback from a tiny drop of blood that got less than 5mm inside.
This simplistic study doesn't speak to the issues at hand at all. It's useless in a court of law. They didn't do their study in hopes it would be cited in a court of law.
To be used in a court of law one has to examine the precise conditions at issue which means the wound itself to assess whether that wound will result in backspatter or not and if so whether it was at contact range and thus the backspatter would go deep inside the barrel. General statistics are useless. Specific statistics regarding a shot to a neck filled with blood would be relevant but that study nor any others have looked at such specific issue. Medical experts are stuck using their expertise to assess such.
That those conducting the study found that most but not all contact wounds result in blood getting in a barrel is meaningless. That a shot to a different location of the body than the neck and an area that was not filled with blood from internal hemorrhaging like Sheila's neck was is totally meaningless. It is like comparing an apple and a Watermelon and conclusion that since you can't bite into a watermelon that you can't bite into an apple.