The Company K Colt 4th Cavalry Single Action Army Revolver

By Rock Island Auction

The Company K Colt 4th Cavalry Single Action Army Revolver
The Company K Colt 4th Cavalry Single Action Army Revolver
Rock Island Auction Company
Rock Island Auction Company

Rock Island, IL –-( On January 23, 1873 an order was placed by the U.S. Government to Colt Manufacturing for 8,000 revolvers “of the new model.”

The first 1,000 would only take Colt 41 days to complete, but before a single one could leave the factory they would of course need to be inspected. Enter one Orville W. Ainsworth, the civilian “Principle Sub-Inspector” for the Ordnance Office of the War Department, who would perform the physical inspections of revolvers numbered #202 – 14,343.

He took ill before he could finish inspecting the subsequent contract renewal, but his stamp was still used until that renewal was finished. According to A Study of the Colt Single Action Army Revolver, that means that the actual dates of service for Ainsworth (and not his stamp) were from mid-October 1873 until November 7, 1874. If you’re wondering why any of this matters, there are two major reasons.

This limited use of Ainsworth’s “A” inspector stamp makes revolvers bearing them rare, collectible, and valuable items.
It was these two large orders of arms that supplied much of the U.S. Cavalry and therefore they saw heavy use in the Indian Wars, including the Battle of Little Big Horn.

When the aforementioned book, an essential resource for Colt SAA Collectors, was originally printed in 1976, only 375 of the original 12,500 Ainsworth inspected revolvers were known to exist in collections, a humbling 3% of the total. As of the 1994 printing of Kopec and Fenn’s Cavalry & Artillery Revolvers: A Continuing Study, that number had shot to 1,655 or 13.2%. One can only hope the number has improved in the near ten years since that book was published.

Lot 3163: Extraordinary Ainsworth Inspected Company K 4th Cavalry Marked Colt Single Action Army Cavalry Model Revolver
Lot 3163: Extraordinary Ainsworth Inspected Company K 4th Cavalry Marked Colt Single Action Army Cavalry Model Revolver

Of these 1,655 known Ainsworth inspected revolvers only 16 of them are known to be stamped on their frame with the text, “CO. K. 4. CAV” When latter of the two books mentioned was published in 1994, there were only 15 known to exist. The example that will be sold in Rock Island Auction Company’s 2013 December Premiere Auction, serial number 3576, is the 16th. The known serial number range spans from 2902 – 4596. This range has perplexed Colt scholars for years, for the following reason. All of the Company K, 4th Cavalry revolvers were ordered on January 15th, 1874 and shipped to the San Antonio Arsenal. Thanks to letters sent at the time, we know that the 6th and 10th Cavalries were each to receive 1,000 of the “new Colt’s revolver,” but that “upon recommendation of the General of the Army, the Secretary of War designates the 4th Cavalry, as the next regiment to receive the Carbines and Revolvers of the new model.” A note on that letter states that the arms to be shipped to the San Antonio Arsenal for the 4th Cavalry, but the specific number shipped is not mentioned. One can assume that a shipment of 1,000 (1,000 per Regiment) was shipped to San Antonio that January. So while existing historic documents would imply that 1,000 items were shipped to San Antonio, the known serial number range spans over 1,700. Were all 2,000 revolvers diverted to San Antonio? Have enough not been uncovered to show us the full serial range? Were the serial numbers sent simply non-sequential? Furthermore, if there were so many, where are the remaining examples? These are all questions that persist regarding these coveted revolvers.

4th Cavalry Colt Revolver
4th Cavalry Colt Revolver

Some credence is given to the “non-sequential” theory by another firearm present in this auction. In lot #1181 is what our headline describes as a “Rare Second Year Production Ainsworth Sub-Inspected Colt Single Action Army Cavalry Revolver with Period Holster.” It has all the early production features, the “A” sub-inspection stamp of Ainsworth, and most importantly, a serial number of 3316. This serial number puts it in the same serial range as the CO. K. 4. CAV revolvers, yet it lacks that rare and desirable marking!

Ainsworth Sub-Inspected Colt Single Action Army Revolver
Lot 1181: Rare Second Year Production Ainsworth Sub-Inspected Colt Single Action Army Revolver with Period Holster. While not marked to a designated unit on its frame, this unaltered, Ainsworth stamped Colt, which falls in the Company K, 4th Cavalry serial range, is still expected to sell for between $10,000 – $20,000.


History of Co. K. of the 4th Cavalry

In 1848, after the Mexican War, the U.S. Army slowly came to realize that it needed additional mounted soldiers as the young country spread Westward. The 4th Cavalry Regiment has its origins in the year 1855, when it was known as the 1st Cavalry, having been formed to alleviate the government’s self-assessed lack of horse borne troops. However, on August 3, 1861 all cavalries were to be renumbered according to seniority. Having been preceded in formation by the 1st Dragoons, 2nd Dragoons, and the “Regiment of Mounted Rifleman,” the 1st Cavalry was re-designated as the 4th Cavalry Regiment.

Immediately after their formation, they spent a great deal of time in Fort Leavenworth, Kansas to help protect settlers from Cheyenne Indians and to help quell any disturbances that would arise from a population heavily divided on the issue of slavery. This newly-formed group possessed the seeds of greatness by having 22 of its 28 officers become general officers serving on both sides of the Civil War including such historic names as Maj. Gen. George B McClellan and Maj. Gen. J.E.B. Stuart. In fact, then Colonel Robert E. Lee commanded the 1st Cavalry for a month before resigning to join the Confederacy.

Sioux War
Sioux War Etching

Prior to the Civil War the 1st Cavalry found themselves split-up with half at Fort Riley, Kansas and the rest spread around the state. During the Civil War, the newly-renamed 4th Cavalry found itself in places stretching from the mighty Mississippi River to the Atlantic Ocean. The earliest Civil War mention (that could be found by this writer) of Company K of the 4th Cavalry is on May 9-14, 1862 where the action of Co. K, as well as Companies B, C, D, G, I, & K, were “present at Corinth, Miss… a detachment under Lieut. Gordon took part in an affair near Farmington, Miss.: no casualties.”

The second earliest mention of Company K occurs at Murfreesboro, TN, during the Stone River campaign (1862-1863) on December 31 1862, when a two-company brigade of the 4th U.S. Cavalry charged “an entire brigade of cavalry and routed them to such an extent that they disappeared from the field altogether.” Company K also saw action at Middleton, TN (May 20-23, 1863), and Okalong, MS in February of 1864. After the Civil War, Co. K. of the 4th Cav is most noted for its campaigns against the Comanche and Kiowa during the early 1870s under Col. Ranald Slidell “Bad Hand” Mackenzie, one of the seven colonels honored by the 4th for their distinction in service. Mackenzie’s fascinating history, stretching from the Battle of Second Bull Run and well into the Indian Wars, is vast, heroic, and documented enough that it could easily fill its own column.

The 4th Cavalry in 1909
The 4th Cavalry in 1909


The condition of this revolver cannot be overstated. The amount of finish is unprecedented and the mature case-hardening provides it a striking ghostly grayed contrast. Lest one think that we are biased in our enthusiasm for this firearm, here are two evaluations from noted industry experts.

“Regarding Subject Revolver; Colt Single Action Army, serial # 3576. In my opinion, This revolver is the finest Ainsworth inspected, U.S. Army marked, Single Action known to exist. It was my pleasure to examine it…”

-A letter dated July 6, 1998 from

Ronald A Ogan, President

Ogan Antiques, Ltd.

“Considering the low survival rate of early US-marked Single Action Army revolvers and considering the exciting and important times in which these revolvers were used, this scare and desirable Colt is an object of considerable significance. The author will be pleased to illustrate number 3376 in the forthcoming revised edition of THE BOOK OF COLT FIREARMS, which will be issued in a two-volume book.

In condition and originality, no revolver equals, or surpasses, number 3376. The color of the blue, the patina of the steel and wood, the old grease from years’ past, and the clouded color the case-hardening (excepting on the relatively bright hammer) are all indicative of the attic-condition, unused survival of this remarkable and rare Single Action Army Colt revolver.”

– R. L. Wilson

Author and Expert

The fact that this gun came to light after so many years of only having 15 examples, in addition to its remarkable condition must have made quite a stir in the Colt collecting community. Its existence alone would be a noteworthy find, but its “finest known” quality truly makes it a special story.

Ainsworth inspected, Co. K 4 CAV Colt Cavalry Model revolver
Ainsworth inspected, Co. K 4 CAV Colt Cavalry Model revolver

A rarity within a rarity that also possesses a fascinating history and some persistent, unanswered questions that have stumped Colt scholars for decades, the Ainsworth inspected, Co. K 4 CAV Colt Cavalry Model revolver is a simply fantastic piece that Rock Island Auction Company is proud to have in its 2013 December Premiere Auction. The 4th Cavalry has served this country since before the Civil War and continues to serve through the current wars in the Middle East. Their history of brilliant and illustrious service is forever noted in the annals of U.S. history and even earned them their own march in 1926 written by the “March King,” John Phillip Sousa, himself a dedicated horseman. That history, combined with an exquisite condition, make this a revolver that will have Colt collectors’ hearts racing. This is one example of the over 600 Colts available in our December 2013 Premiere Firearms Auction, which will contain everything from a near-pristine Colt Model 1851 Navy to a Model 1874 Gatling gun, and SIX different Paterson revolvers!  Click here to search our catalog or use one of our previously created Colt categories such as 1st Generation Single Action Army or Colt – Auto Early.

You’re bound to find something you love!


  • Graham, Ron, John A. Kopec, and C. Kenneth Moore. A Study of the Colt Single Action Army Revolver. S.l.: S.n., 1976. Print.
  • Kopec, John A., and H. Sterling. Fenn. Colt Cavalry & Artillery Revolvers: A Continuing Study. 1st ed. Vol. 2nd. Whitmore, CA: J.A. Kopec Publications, 1994. Print.

Rock Island Auction Company has been solely owned and operated by Patrick Hogan. This company was conceived on the idea that both the sellers and buyers should be completely informed and provided a professional venue for a true auction. After working with two other auction companies, Mr. Hogan began Rock Island Auction in 1993. Rock Island Auction Company has grown to be one of the top firearms auction houses in the nation. Under Mr. Hogan’s guidance the company has experienced growth each and every year; and he is the first to say it is his staff’s hard work and determination that have yielded such results. Visit:

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VT Patriot

Fantastic piece of American history. If that gun could only talk. And a great historical presentation.


I have always,said I was born 100’s to late.


The history of the past, comes alive once again.