I am going to go for the middy. Got a little carried away looking at the 12" rail. :D
Not sure what I would use it for anyway! Regarding the barrel on the M4 from the DD site:
Barrel: 16″ Ordanance Grade 4150 MP Tested, Chrome Lined, 1:7 Twist, M4 Profile
Thanks for the input on the DD. Top Shelf Rifle is what I'm looking for!

