Cowboy Options: Buy R&D Gunshops 1851 Navy Conversion

Kenny Howells reworked cowboy conversion is superb, but pricey; Cimarrons gorgeous Open Top is a best buy. One EMF revolver is worth a look, but you should pass on a second.


Shortly after the advent of Colt’s Model P Single Action Army, range-riders, lawmen, desperadoes, and even average citizens suddenly wanted a revolver that handled the new self-contained brass cartridges. However, many shooters liked the feel of their old Navy or Army cap-and-ball six-shooters, and didn’t want to give them up all that quickly. Solution: They could have their percussion pistol converted to a breech-loader.

During the 1870s, many percussion revolvers were converted to handle cartridge-type ammunition. Gunsmiths drilled out the existing percussion cylinder, added a breech plate with loading gate and ejector rod, and fitted a firing pin to the hammer. Afterward, the old muzzleloader was able to fire cartridges. The advantages were faster reloading, and the shooters didn’t need to carry loose powder, caps, lead balls, and the tallow-soaked over-powder patches common to the percussion pistol.

Several prominent gunsmiths and a few factories specialized in these conversions, the names of Richards, Richards-Mason, Thuer, and Colt’s own factory being prominent. The Colt factory also made, for a short time, a handgun that was the last of the open-frame Colt revolvers ever made—until the introduction of the 2nd Generation Navy a few decades ago. This was the Colt Open Top, or Model 1871-72. Colt’s made about 7,000 of them from 1872-1873, until the famous Model P (SAA) came out.

The original Colt Open Top was chambered for .44 Rimfire, and had a six-shot cylinder and 7.5-inch barrel that were both specifically made for the Open Top. The grips were varnished one-piece walnut. The other parts had finishes common to all Colt handguns of the period, such as case-hardened hammers and frames, and with either blued steel or silver-plated-brass grip straps. Identifying features include a straight-sided—not rebated—cylinder, and a rear sight integral with the rear of the barrel.

These guns are extremely rare today, more so than the scarce original conversions. While some owners of original conversions and Open Tops shoot them with loving care today, we feel it’s not a good idea to subject them to the abuse of a typical Cowboy Action event. If you want to shoot a conversion a lot, there are modern replicas made that will fill the bill, and we recently tested a few of the old conversions and Open Tops available to today’s cowboy.

Most of the modern guns are chambered for cartridges that don’t require the old heeled bullet, so reloading for them is not much of a chore. However, all of them, new and old, are built around guns designed for use with black powder only or, at best, the weakest smokeless loads designed specifically for Cowboy Action shooting. No Plus P loads here, or anything approaching high pressure.

We were able to obtain two conversions for testing. To our extreme good fortune, one of them was the personal handgun of Kenny Howell, headman of R&D Gunshop, the premier maker of custom percussion conversions in the world today. Howell has been very busy building guns for Tom Selleck to use in a movie being filmed in Canada, and we thank him for courteously loaning Gun Tests his personal sidearm. Otherwise, we wouldn’t have been able to include a product from what is widely regarded as the top conversion shop in the country, and perhaps the world.

His handgun was built on a 2nd Generation Colt 1851 Navy, had a 4.75-inch barrel, and was chambered for the .38 Long Colt. The second conversion in our test was a reproduction marketed by EMF Co., and was built by the Italian firm of Armi San Marco. It had the original 7.5-inch barrel length of the 1851 Navy on which it was based, and was chambered for .38 Special.

Cimarron Arms’ entry was a lovely charcoal-blued copy of the Open Top, in .38 Special, made by Uberti. Finally, we had another Open Top, this one another EMF made by Armi San Marco. Both of these Open Top clones were chambered for .38 Special. Please note, it is mandatory to load only five shots into these handguns and carry them with the hammer down on the empty chamber. The Cimarron and EMF Open Tops have safety devices built into their hammers that require turning a screw to extend a hammer block forward from the front of the hammer. This prevented the hammer from moving forward far enough to strike a primer. Neither of the conversions had any safety devices built into them, but we had no problems with that.

We first look at the conversion products, which are derived from percussion-style designs.

R&D Gunshop 1851 Navy
Our recommendation: The $1,400 R&D Gunshop Conversion by Kenny Howell had a 4.75-inch barrel and extra-cost real ivory grips. This handgun felt and looked exactly right, and handled and shot best of the test. It gave a feeling of great integrity, as though the gun were built correctly to last a long time. It was a fine-looking and fine-handling winner. We’d buy it if we wanted the best conversion available today.


This one began life as a 2nd Generation 1851 Colt Navy, which Howell converted to .38 Long Colt. In the process, Howell not only shortened the barrel but installed his personal preference of real elephant-ivory grips. These were carved with an eagle and shield on the left side, and remained smooth on the right. They added some weight to the gun but the balance was just right. The hammer had a firing pin inserted from the front, and double-pinned in place. Howell had rebuilt the gun from the ground up, including reshaping many of the parts and completely refinishing the gun.

Several things about this handgun came immediately to our attention. It looked and felt very good. It had quite a bit of weight, and we thought—correctly—that it would have almost no recoil. The fit and finish of this handgun were very well done. Howell had replaced the small square-backed trigger guard with a later-style rounded guard to give more finger room, and the worn silver plate on the grip and guard indicated this gun had seen considerable use. However, it was still very tight, and indexed perfectly. The flats on the barrel were indeed flat, and the case coloring was nicely done.

The front sight consisted of a dovetailed front insert with a very thin profile. The front sight blade was so thin we had a hard time seeing it well enough to get consistent elevation, though this was less of a problem in very bright sun. The rear sight was a notch in the hammer.

On the range, loading and unloading the gun was not quite the same as for a SAA Colt. We could not back the cylinder up against the hand to index it for fast ejection, because then the ejector rod didn’t line up with the cylinder. We have no doubt this is how they used to be, and in fact the EMF version handled just the same. Loading it was easy enough, the gate giving plenty of room for the cartridge and the thumb. The trigger pull of the R&D Gunshop Conversion was a bit creepy, and broke at just over 2 pounds.

The gun shot about 2 inches high for us at 15 yards, but was perfect for windage. It was pretty accurate, too. Our best five-shot group was 1 inch at that range, and average groups were 1.5 inches. The Black Hills ammo that came with the gun sent its 158-grain LRN bullets across the chronograph at all of 613 fps, which gave a muzzle energy of 132 ft.-lbs. Recoil and report were very light.

Howell told us to not disassemble the gun for cleaning because that would add to the wear of the mating parts, which would cause the gun to become loose before its time. The gun and especially the barrel stayed quite clean during our testing.

The main thing about this handgun was that it gave the shooter a feeling of confidence. The more our individual shooters fired it, the more they liked it. It pointed well enough that rapid-fire hip shooting gave good hits at across-the-table ranges. The 4.75-inch barrel length was much handier than that of the other three test guns, and we wonder why the long 7.5-inch-barrel version of the Colt SAA was so popular when that gun first came out. We suppose it was because shooters were used to the long barrels of the 1851 Navy and 1860 Army, and because the average pistol shot would be able to make hits easier with the longer barrel.

EMF 1851 Navy Conversion
Our recommendation: When one buys a new handgun, even for the moderate $280 price tag of the EMF 1851 Navy Conversion, one expects it to be complete and fully assembled. Unfortunately, our first glimpse of this gun in its box showed two separate parts. The front sight was lying in the box next to the rest of the gun. However, looking past that, and past the rounded corners on the trigger guard from too much buffing, we also saw a very attractive handgun that we’d buy if we wanted a bit of history for occasional shooting, without busting the bank.


Silver plate graced the nicely contoured brass grip strap and trigger guard, and dark but rich case colors highlighted the frame, recoil plate and hammer. The bluing was well applied to the sharp-cornered, well-polished barrel and to the roll-engraved cylinder. The rolling was a bit faint, with some of the tiny details missing. The one-piece plain walnut grips were nicely contoured and dull-finished, but with some porosity. The hammer was sharply checkered. Timing was good, though it was necessary to pull the hammer fully rearward to get the bolt to drop into place. We’d rate the overall fit and finish as very good.

The front sight was supposed to have been soldered to the barrel. There were no threads on either the front sight or in the hole in the barrel. We decided to epoxy the sight in place for our testing, and it stayed there throughout all our firing. If we owned the gun we’d solder it in, although this could mar the bluing. The rear sight was formed into the top of the recoil plate, and was shaped like a wide V. The sight picture was not modern, but adequate.

The effort to cock the hammer of the EMF Conversion was so slight we wondered if the gun would fire reliably. The trigger pull had lots of creep and a very light letoff. It broke at about half a pound, much too light for general use. The firing pin was captive in the recoil shield. The face of the hammer was flat, and had a hardened insert where it struck the pin.

If it matters to the shooter, the barrel lug on the EMF Conversion was never cut for a loading rammer. By contrast, the cut on the Howell/R&D gun was filled with a steel plug. This EMF barrel was one piece of steel, and hence the gun was never actually a percussion revolver in the first place, and thus is not technically a correct conversion.

On the range, this handgun was pleasant except for two things. One, it hit a full 5 inches to the left of where it looked at 15 yards (our front-sight repair had nothing to do with that). Two, it was a real bear getting fired cases out of the gun. However, it did go bang every time we tried it.

Cimarron Open Top
Our recommendation: The charcoal-blued $494 Cimarron Open Top .38 Special was well worth its price. This lovely piece of work had a magnificent light blue color, but the case colors were muddy and a bit pale around the edges. Still, the gun looked great, had a nice “hang” in the hand, shot well, and was reliable. We believe it would provide the modern cowboy with a fine alternative to the usual SAA. We’d buy it.


The Cimarron Open Top had extremely well-fitted, well-finished, one-piece, modestly fancy walnut grips that perfectly complimented the light-blue color of the steel. Every steel part except for the case-colored hammer and frame was finished in charcoal blue. The true-blue color of the steel is the result of heat oxidation, not hot dipping. We cannot imagine a more attractive or appropriate finish for a handgun of this type. However, it seemed to be not very durable. It cannot be touched up with cold blues, and the use of cleaning fluids such as lacquer thinner or acetone will remove the finish. We had the gun in a drawer for a few days, with the barrel in contact with a flexible electrical wire. The action of opening and closing the drawer caused a slight blemish in the bluing. Another normally blued handgun had previously been in that drawer in the same position for over a month, and its bluing was unharmed.

Although we thought the Open Top was somewhat heavy for .38 Special, it had a solid muzzle-heavy balance that gave it a good feel in the hand. It gave stability and pointability that Cowboy Action shooters should be able to put to serious good use.

Cimarron/Uberti, please note: Although the fine attention to detail is quite remarkable on this handgun, and you get our sincere applause for that, the back strap of your gun comes too far down, resulting in a profile that screams something is not quite right. The bottom of the grip ought to parallel the barrel, or be pretty close to it. Yours does not, and this condition needs fixing to perfect the look of the gun. The same fault marred the contours of your 1851 London Navy percussion revolver that we tested recently.

However, the trigger guard and back strap fit the frame perfectly, with no polishing depressions. This was high-quality work. The fit of the frame to the barrel was nearly, but not quite, as good as the fit of the trigger guard and backstrap. We rated the fit and finish as excellent overall. The details were also pleasant to note, with the correct 1871 and 1872 patent dates on the left side of the frame, the proper contour to the loading gate, and “38 CAL” on the top left flat of the trigger guard, although this probably would have said “44 CAL” on originals. The steel grip strap was polished flat on the bottom, and the screw holes showed no dishing.

The front sight was a silver-colored insert of rounded shape that presented a slant-sided flat-top post when viewed through the V-shaped rear. The front sight blade caught too much light, so we blackened it for our testing. The rear sight was integral with the rear of the barrel, just like it was on originals. A somewhat stiff loading gate opened at the right rear of the frame for loading. This remained stiff, and was the only part of the gun that needed attention. Its joint with the frame was perfect, even better than the high-dollar R&D Conversion. The hammer had slippery checkering, but the old percussion-style hammer with its sharp hook shape was easy to cock.

As on original Open Tops, the Cimarron’s cylinder was roll engraved with Ormsby’s naval battle scene of 1843. This was very evenly and cleanly done, with all the action and details visible. Solely judging the gun on its looks, we’d be proud to own it.

But we also like it when a gun shoots well, and the Cimarron didn’t disappoint. We found the trigger pull to be quite good. There was no creep, and it broke at 3.5 pounds.

With two types of the lightest-power commercial .38 Special match ammunition we could find (PMC and Federal), we found the Cimarron Open Top to give 1.9-inch average groups with PMC ammo. With the Federal wadcutters the accuracy average was 1.7 inches, though these groups were 4 inches high and 2 inches right of the aim point. With the PMC 158-grain load, the impact was 2.5 inches higher than the sights looked, and 1 inch right, which was close enough for this type handgun.

There were no problems loading or shooting this one, but unloading the fired cases was a knack we never got used to with this or any of these test guns. If we owned this one we’d try Black Hills cowboy ammunition for it, and also black-powder loads for pure authenticity and maximum power. With our test ammunition recoil was very light.

Cleaning was accomplished by following the instructions that came with the gun. We turned the flat-sided screw above the barrel wedge, removed the wedge and pulled off the barrel and cylinder. We found this to be straightforward. Reassembly was just as easy.

EMF Open Top
Our recommendation: With a list price of $300, the EMF/Armi San Marco Open Top didn’t have the fit or finish of the Cimarron, but we didn’t expect that on a gun that cost nearly $200 less than its competitor. However, we expect any handgun to fire every time we press the trigger, and this one didn’t. We could not get reliable ignition from the PMC ammunition, each cartridge requiring two strikes of the weak-springed hammer. The Federal wadcutter went off most, but not all, of the time. This is a dangerous situation, for many reasons. Unless EMF could change the innards to make this gun reliable, we can’t recommend buying it.


Although metal polish, bluing and case coloring were pretty good, the attention to detail was not as high as that of the Cimarron. However, we wish Cimarron/Uberti would do as good a job of case coloring as does EMF/Armi San Marco. The colors here were rich and full. Also, like the grips on the EMF Conversion, these one-piece plain walnut stocks were well fitted and well contoured, but lacked complete filling on the dull finish. The pistol grip and back strap were silver-plated brass, a viable alternative to the all-steel of the Cimarron. Genuine Open Tops had both types of grip.

Overall fit and finish of wood and metal of the EMF version was very good, and the metal fit was somewhat better than that of the EMF 1851 Navy Conversion. The folks at Armi San Marco need to assemble the guns before polishing them to avoid rounded edges.

Like on the other EMF gun, the spring pressure on the hammer made us wonder if the EMF Open Top would fire. It didn’t. The hammer had a distinct sticky spot on the way down, and if we let the hammer down easily, holding the trigger fully back, we could stick the hammer in mid-fall by the friction inside the gun. The hammer was nicely checkered, timing was good, and lockup was very tight. The trigger pull was very creepy, very light—about 1 pound—and not at all good.

The sights were correct for the type, consisting in a curved white-metal front blade and a barrel extension rear. Like the sights of the Cimarron Open Top, the overall sight picture of the EMF version left much to be desired. The rear notch was too narrow, and the top of the rounded, shiny front blade disappeared in bright light. These are, we suspect, very much like the original frontiersmen had to deal with. We have no doubt the sights of all of these guns detracted from our ability to wring out the most they had to offer.

On the range, we found the gun to be extremely accurate for the three five-shot groups we fired before we quit trying altogether. The only one we managed with PMC ammunition went into 1.5 inches. Best group of the entire test series was the last one with Federal wadcutters, with five into 0.9 inch. The remaining five-shot group measured 1.7 inches with the Federal WC ammo. It’s a pity the gun would not work all the time, for it had lots of promise.

Gun Tests Recommends
Our recommendation on the two Conversions are that you are going to get what you pay for.

R&D Gunshop 1851 Navy Conversion, $1,400. If you want a Conversion that will always shoot, that will last a long time, and that is historically correct, you have only one option. Get one from R&D Gunshop. It will cost you around $1,400 without ivory grips. We feel one of these guns will last several lifetimes because everything about them, inside and out, is rebuilt. They are remanufactured. That means old parts are refitted, rehardened, retimed, repolished and reblued. Also, many new parts are made for them. That’s what you’re paying for. Howell tells us he won’t work on most of the new guns because they don’t have the quality of steel he’s looking for. Other than a knife-like front-sight blade and a bit of creep to the trigger, we could find no fault with it. Buy it.

EMF 1851 Navy Conversion, $280. If you want a good look at history and don’t expect to shoot the dickens out of the gun, which means you won’t have a whole lot of Cowboy Action shooting on your agenda, you might be happy with the $280 EMF 1851 Navy Conversion. It’s an attractive handgun that will undoubtedly need some fiddling with to make it just right, but it’s a pretty nice gun for not much money. In spite of its hitting so far to the left and needing work on its too-light trigger, the EMF Conversion was a bona-fide 2-inch grouper with PMC ammunition.

We advise the prospective purchaser of any of these old-style handguns to prepare himself for a bit of study in the best way to load and unload them. We have no idea how to make this gun shoot closer to the point of aim, but we thought it represented a good glimpse of a transitional design in firearms history, and was worth its modest price. We’d give it a Conditional Buy.

Cimarron Open Top, $494. Concerning the two Open Tops, we’d buy only the Cimarron. It is clearly superior to the $300 EMF version, in our estimation. If you want to save money on your Open Top, get the Cimarron without the fine charcoal bluing for about $50 less. Bottom line here is that for $494 you get a great-looking, thoroughly historical handgun that ought to make anyone who owns it very happy. Take good care of that oxidized finish on the Cimarron Open Top and it’ll look good for a reasonable time, but expect holster wear pretty fast. However, this honest wear may actually add to the “frontier” appearance of the gun.

EMF Open Top, $300. We found the EMF Open Top unacceptable because of reliability issues, and we wouldn’t buy it.






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