Boyce is a ballistics expert not a pathologist. 11 years ago Boyce was claiming the marks were caused by the barrel of the rifle having been heated up.
Yes but three problems occurred.
Firstly, the peer reviewer advised more experimentation was required to confirm this - but the CT ran out of time / funding.
Secondly, the only way to heat the end of the barrel to sufficient temperature would be by using the Aga.
Thirdly, in more recent times the Aga itself has come into focus as a potential cause.
Point 1 somehow allowed the CCRC to ghost all the expert evidence regarding Sheila's throat. Which has been left unchallenged.
Start at the oldest articles on CCRC Watch and work your way up. Only then will you understand the claptrap about the blood in the SM being stronger than the burns experts.