New Barrel for Remington 870 for Trap & Skeet Shooting

[Virginian]

Any 870 barrel other than a 3-1/2" SuperMag will fit. They might too, I just don't know. Don't see your picture. A vent rib is a raised rib that runs the length of the barrel, supported by posts at about 2-1/2" intervals. Aids in wingshooting.
The best choice for clays in my opinion would be a Light or Target contour barrel, but they run $225 plus, new. Any RemChoke fitted barrel will do well though. You can change the choke to suit your needs. A fixed choke is cheaper but wouldn't be best because skeet and trap are at opposite ends of the spectrum.
Look on www.gunbroker,com, www.corsonsbarrels.com, and www.barrelexchange.com. A used barrel will work fine and save you mucho dinero. There are over 10,000,000 870s out there and heaven knows how many barrels. Good luck.