You can get a lot of good info on Delta from Charlie Beckwith's book
Delta Force, and Eric Haney's
Inside Delta Force.
These guys shoot A LOT. More than just about anyone else other than maybe DevGru or the SAS. I think Guns 16 is skirting the bottom...18 is what the Assaulters need to have to realistically be able to execute the hostage rescue stuff they train for.
A lot of the other stuff looks spot on.
I have to leave the house for a bit, but I'll have some more feedback later on this evening.