If they are really big, aren't they raven's then?
I hate 'em all though, noisy as hell, but smart and warry...hard to get a drop on 'em on the spur of the moment...though up at the lake I still try...they stay deep enough in the trees to make a shot hard.

PS-All the shotgun does is drop a lot of tree branches in your yard you have to clean up!
Maybe they are ravens, I don't know the differences. I DO know they're a pain in the ass.
I wasn't planning on using a shotgun anyway; we already have enough of Mother Nature's tree-mess to clean up as it is.
Physical Differences: Crows average around 17 inches long, and ravens about 24-27.
A raven weighs about four times that of a crow.
Crows have a wing span around 2.5 ft., and ravens about 3.5-4 ft.
A raven's wing sometimes makes a prominent "swish, swish" sound, while a crow's wingbeat is usually silient.
Ravens have pointed wings, while crows have a more blunt and splayed wing tip.
Crows have a fan-shaped tail (squared-off), while raven tails are long and wege-shaped.
Besides having a bigger, more powerful bill, a raven's bill is curved, while a crow has a more-or-less flat bill. Additionally, atop a raven's bill is a tuft of hairs absent on crows.
As a result of being larger and more powerful, ravens are the more efficient predator. (Predation is a very small percentage of crow and raven diets.)
http://www.angelfire.com/id/ravensknowledge/ravensvscrows.html