What model is this shotgun?

[Researcher]

E. Remington & Sons made five variations of their Whitmore "Lifter Action" hammer double barrel shotguns. April 16, 1872, was the date U.S. Patent No. 125,775 was granted to A.E. Whitmore covering the "Lifter Action". August 8, 1871, was the date U.S. Patent No. 117,843 was issued to A.E. Whitmore, and may have covered some elements of the locking bolt of the guns. Those two patent dates are found on the watertables of all E. Remington & Sons hammer doubles, both the five "Lifter Action" models and the four "Top-Lever" models.

The original gun, now known as the Model 1873, did not have rebounding locks. There were projections on the side of the plate that moves rearward when the lifter is raised, and these projections engaged flanges on the inner edges of the hammers and raised the hammers to half-cock. On April 27, 1875, L.L. Hepburn was granted U.S. Patent No. 162,473 which covered the rebound locks used on all the later Remington hammer doubles. The later "Lifter Action" guns, with rebounding locks, were the Models 1875, 1876, 1878 and 1879. The Models 1878 and 1879 have T-shaped rib extensions. Serial numbers don't help much in differentiating these models, and we really need to see several good pictures of your gun to tell which model you have.

[Researcher]

Now that you've added a picture, I'll say Model 1875 and probably a Grade 4. Very nice shotgun.