The Remington Hammerless Doubles had three styles of barrel lugs over time. Some of the early guns had the typical Purdey double under-bolts as my 1895 vintage BE-Grade --
101315 BE-Grade 12-ga 07.jpg
Charles Semmer in his book
Remington Double Shotguns called these "bridge frame guns."
Most had the web between the lugs making the forward bite into two smaller bites --
112429 01 EEO-Grade, 16-gauge, 30-inch.jpg
Some of the late K-quality guns eliminated the forward bite altogether. My 1909 vintage KE-Grade 16-gauge --
Q380786 05 single barrel lug.jpg
I have recorded an 1898 vintage 10-gauge with this style lug and Remington Steel barrels, making it an AER-grade, which I suspect was rebarreled at some point in time.