Send this pic to David Whelan and make his head explode. :)
You are correct what would David Whelan do if the shooter had been a hand-loader and used 6 different bullet types.
Then loaded them in 6 different makes of brass. Some brass some nickel. With different primers and powders.
Thousands of combinations.
Just proves David Whelan knows nothing about firearms.
Criminals often use different ammo or even the wrong ammo for the firearm in use.