Detection of Bone and Bone-Plus-Bullet Particles in Backspatter from Close-Range Shots to Heads," Journal of Forensic Sciences, Vol. 36, No. 6, 1991, pp. 1745-1752,

Of course that tells me everything I need to know?

Post up the link or shut up!
You have quoted VDM in the past, I've read your back posts, re blood found inside firearms. It happens a % of the time not all the time. My view is a person's physiology plays a part which means every case will be different and can't be generalised.
In any event Ed Lawson challenged Malcolm Fletcher on all of this at trial.