These revolvers and their ammunition were manufactured from 1864 to 1870 by Moore's Patent Firearms Co. and National Arms Co. to circumvent the patent held by Smith & Wesson that prevented other companies from legally manufacturing revolvers with bored through cylinders. The barrel has a blade front sight and "NATIONAL ARMS Co BROOKLYN. N.Y" marked on top, the cylinder marked with the Williamson patent on the rear edge, intricate floral scroll engraving patterns with punch dot backgrounds on the frame, entirely silver plated, and smooth grips. The grips are marked "HY/64" on the back, and "HY64" is stamped on the left side of the grip frame and back of the cylinder. The full serial number is on the bottom of the barrel.

Very fine, showing 90% plus of an attractive, original age-darkened, antique silver with the balance thinned to show an attractive patina mainly at the edges and some scattered light pitting. The grips are fine with some minor dings and scratches, and retain most of the varnish. Mechanically excellent.