Remington Arms Co. began offering a vent rib on their Remington Autoloading Shotgun in 1910.
1910 Remington Autoloading Gun Ribs.jpeg
I have never seen one of these barrels with the widely spaced posts.
The next year Remington Arms - Union Metallic Cartridge Co. showed the closely spaced posts we see to the end of production.
1911 - 1912 Ribbed Barrels.jpeg