The Remington Hammerless Double originally was introduced in October 1894 in five grades from A- up to E-Grade in 10- and 12-gauge with Damascus barrels and the option of ejectors. These guns have serial numbers in the 100000 range. In their April 1897 Catalog Remington Arms Co. began offering two grades of steel barrels -- Remington Steel and Ordnance Steel. Remington Steel barrels were the same price as the Damascus barrels on the entry-level A-quality guns while Ordnance Steel barrels were $5. extra on both A- and B-quality guns. Ordnance Steel barrels were the same price as Damascus barrels on C-, D- and E-quality guns. In the fall of 1897 Remington Arms Co. began offering the Remington Hammerless Double in 16-gauge.
A lower priced version of the Remington Hammerless Double in 12- and 16-gauges was introduced on an insert in some of the 1899 catalogs. These are the K-grades and have serial numbers in the 300000 range. These guns have J-spring snap-on/-off forearms instead of the Purdey-style push-button forearms of the A- to EEO-Grades. These guns were initially offered in two styles, the K-Grade with extractors and Remington Steel barrels and the KED-Grade with ejectors and Damascus barrels.
In the first 1902 Remington Arms Co. catalog a new high end, $750 list price, 12-gauge, ejector, Remington Hammerless Double, the "Remington Special" was introduced. These guns have serial numbers in the 400000 range. They generally have a Greener cross-bolt. The 1902 catalogs state Nickel Steel Barrels, but by the 1903-04 catalog Nickel, Ordnance or Whitworth barrels were being offered. One "Special" with Damascus barrels has been observed.
In the 1903-04 catalog a third variation of the low priced gun, the KD-Grade with Damascus barrels and extractors were added to the offerings.
In the first 1906 Remington Arms Co. catalog, a final variation of the low priced gun was added the KE-Grade, a Remington Steel barrel gun with ejectors. In the same catalog they introduced a new lower priced, $60 list price, straight-gripped, Trap Gun to the line called the FE-Grade. It has just a bit of border engraving, a bit less then the B-quality guns.
Remington Arms Co. only used the terms "Model 1894" and "Model 1900" on parts lists, on the catalog pages they were referred to as the Remington Hammerless Double Barrel Shotgun and just differentiated by grade.
According to Charles Semmer, late in production a few 20-gauge K-quality guns were made in 20-gauge and a few high grade guns, like the one that started this thread, were barreled with Krupp Fluid Steel tubes.
Single triggers were never cataloged but a variety of single trigger patents were assigned to Remington Arms Co. By the number of guns seen with single triggers they must have been actively experimenting.