I read a wonderful article on Terminal Ballistics written by a former LEO who now works in a morgue.
We have discussed this before and it has had some mixed views on authenticity and accuracy.
http://thefiringline.com/forums/showthread.php?t=293788&highlight=terminal+ballistics+morgue
So before thinking this is such a great article, do consider that there are those problems plus problems of the data.
He writes about first-hand witnessing of many, many gun shot deaths and the evidence those leave as to caliber, placement and bullet type.
Also note problems with your own perspective. The guy likely did not witness a single death. You see, coroners and medical examiners show up after the deaths have occurred. So this guy isn't seeing what is going on premortem and antemortem (at around the time of death). He knows people are dead, but not necessarily how quickly their deaths resulted or how much carnage was done before death.
As a cop, he may have witnessed some gun-shot deaths, but generally speaking, no cop ever witnesses very many gunshot deaths over their entire careers and of those that witness people dying from GSWs, even few witness the GSWing event.
I see an average of 8.2 autopsies per day/365 days per year, and I can tell you that when the chips are down, there's nothing that beats a 12-gauge.
Here, the author is sort of fudging. The numbers of autopsies makes it sound like the guy is doing them and he isn't. He may see 8.2 autopsies a day like the head of my auto service place sees about 70 cars a day.
What does 8.2 autopsies a day look like logistically? That is about 3000 a year and the offices that run that many are staffed with 10-15 forensic pathologists to handle the load (on average) plus a large administrative staff. Nobody works 24/7/365. At best, the guy signs off on the reports and so likely isn't even witnessing all the autopsies first hand.
http://www.npr.org/buckets/news/2011/01/coroner-stats/county-table.php?year=2005
Looking at 8.2 autopsies a day another way, how many are actually gun-shot related? Heck, the FCME in Atlanta has a pretty heavy load, but maybe only 1/3 of the autopsies are homicide/suicide-related and obviously not all of those are going to be firearms-related. So the notion of the oh-so impressive number of 8.2 autopsies a day comes down to 2-3 folks who might have died intentionally and some lesser number that were firearms-related.
The guy is throwing out the 8.2 a day because it is the only number he may have (assuming it was even real) because he doesn't actually have any quantified terminal ballistic information.