[Setters4Life]

Just get an 870 barrel threaded for choke tubes if you want some versatility. As for 3 1/2" chamber needs, you don't need this type of firepower for crows. They'll end up having the last laugh as you'll be in the poor house buying expensive shells.

Nothing wrong with a 2 3/4" chambered 12 ga. or a fixed-modified choke either. That combination can probably serve you well for most situations for crow with the right loads.

I was out varmint hunting in the snowstorm Friday, and managed to call some birds in and connected with one. All I used was an old 16 ga. w/ fixed modified choke:

 

[Setters4Life]

I would guess 40 yards. He was incoming above the treetops in a mature forest and out a ways from me. (He was pretty small-looking when I passed the bead through him.) I was using a duplex reload I concoct myself; 3/8 oz. of #6's over 3/4 oz. over #7 1/2's. Total payload is 1 1/8 oz. and it's moving at only 1200fps.

Remember, it's not the size of the shell that reaches out at any distance, but the size of the shot you are using and the energy it has at that distance.

I do prefer #6's and #5's for crow and have seen #5's reach out pretty far to fold birds. There's not much to a crow, they are pretty frail when it comes to bone structure yet they represent a small target.

I kill a few crows each year with a 20 ga. shooting 1 oz. reloads with #6 & #5 shot out of a modified fixed-choke A5. You don't need much, just the right loads.