Colt Forum banner
1 - 6 of 6 Posts

689 Posts
Discussion Starter · #1 ·
This is the 2nd of two Diamondback Articles that tommix has provided...

Colt’s Striking Diamondback

When you consider the degree of popularity Colt’s Diamondback has enjoyed since it was introduced in 1966, the fact that 140,000 have been produced comes as no surprise. ST’s Dick Metcalf puts two test .22s (four- and six-inchers) through their paces, and the results of his efforts illustrate the importance of judging a gun on anon anon an individual basis.

By Dick Metcalf

COLT FIREARMS has a knack for making better-than-average handguns. It may not offer as many calibers or model variations as some other manufacturers, but many of the guns in Colt’s line have near-legendary status among shooters.
For example, take this trio:
• The .45 Single-Action Army revolver carries the history and heritage of the American frontier and Old West.
• The Colt .45 Auto is one of the most-used and imitated firearms in existence, and surveys have repeatedly shown it to be the best-known handgun in the world.
• The Colt Python .357 Magnum is regarded by many as the highest-quality production revolver made.
Another classy product for Colt is the Diamondback, a scaled-down version of the .357 Python. It’s built on the small Colt “D” frame and is currently available in .22 LR and .38 Special calibers, in either four- or six-inch barrel lengths, blue finish only.
The Diamondback was introduced in 1966 and first cataloged the following year. Colt’s intention was to offer a lighter weight, service-use, small-caliber gun that would provide target-grade accuracy and capitalize on the vast popularity of the Python’s appearance and styling. In terms of looks, they certainly succeeded, for the Diamondback is a virtual twin of the Python.
Like the Python, the Diamondback sports a heavy, un-tapered barrel with a full-length ventilated rib and front-sight ramp. The extractor-rod shroud is solid steel and runs full length under the barrel, adding a comfortable, muzzle-heavy feel to the gun’s handling characteristics. The square-cut muzzle crown extends slightly beyond the face of the barrel.
The rear sight is the Colt “Accro,” fully adjustable for windage and elevation with positive-click locking. The front sight is a small ramped blade only .12 inch high. The low profile of the blade is necessitated by the height of the ventilated rib and the ramp base. On a larger caliber gun used for long-range shooting, the short sight could be a drawback, preventing a good sight picture when elevating the front blade for extended shots, but it should be no problem on a .22 or .38.
The hammer on the Diamondback has a wide, grooved target-style spur extending far back in a low arc, making single-action cocking very easy when the gun is held in a shooting grasp. The hammer is the only part of the gun that is brightly polished; the rest is blued. One notable feature of the hammer is the blade-type, solid-mounted firing pin. Also, the Diamondback is the only DA .22 currently manufactured that does not feature a frame-mounted firing pin or a transfer-bar ignition system.
The Diamondback’s trigger is a narrow, service type width with a smooth surface and a blue finish. I would prefer a slightly wider trigger on a target-style handgun, but no such option is available from Colt.
The cylinder opens by swinging out to the left and is released by the standard Colt latch at the rear of the cylinder on the left side of the frame. The latch operates by being pulled backward instead of the forward-release motion found on S&W and Ruger DA revolvers. This design is a result of the cylinder-locking system which holds the cylinder in place only at the rear; there is no latch at the front of the ejector rod (also unlike other common DA revolvers).
I have never been fond of the Colt cylinder-release system because of the sharp corner on the latch which tends to dig into the thumb when pulled. Colt has recently changed the design of this latch spur on the Python, making it beveled and more rounded. I hope the new style will also be applied to the Diamondback and other Colt revolvers like the Trooper and Lawman.
The rear of the cylinder on the Diamondback is fully counterbored to enclose the cartridge case heads, a feature not really necessary given the case head strength of modern ammunition, but it does add to the solid, gap-free, overall appearance of the gun and to its already pleasing esthetics.
The fit and finish of the Diamondback are excellent. All parts and screws are hairline mated, and the wood-to-metal fit of the stocks is close and precise. The finish is a deep, lustrous, high-polish blue, fully equivalent to the famed Python finish. In short, the Diamondback is a truly beautiful revolver.
The only feature of the Diamondbacks I don’t like is the design of the stocks. Like the Python’s stocks, they are an oversized target style with a wide flare toward the butt and crisp, sharp-raised checkering. When shooting .357 Magnum loads in a Python fitted with such stocks, the raised checkering digs into the palm of the hand, especially where the checkering corners at the upper rear surface. With the light-recoil .22 LR and .38 Special Diamondbacks, of course, the “sandpaper effect” of the checkering is not nearly so noticeable, but the butt of the stocks still makes it virtually impossible for any shooter (except one with extra-large hands) to get any grasp support from his third and fourth fingers.
On some recent-production Diamondbacks, I have noticed the stock profile has been altered somewhat, reducing the extreme flare of earlier models. The improvement in “gripability” is notable, though still not as natural as I would like. Shooters with other hand sizes may be even more satisfied.
The 1980 Colt catalog, incidentally, shows both types of stocks on the two Diamondbacks pictured, and the Diamondbacks I have recently seen in gun-shops (.22 and .38 versions) feature both stock styles in an apparently random distribution.
The Diamondbacks, in both calibers, have been very popular since they were first introduced. Approximately 140,000 have been manufactured to date. In addition to the four and six-inch blued versions currently available, several other Diamondback variations have been produced at different intervals over the years.
From 1966 to 1970, both the .22s and 38’s were made only in blued 2 and four-inch styles. During 1971, nickel finish was added as an option. In 1972-73, the 2 inch .22 was dropped from production, and nickel finish was available only for the .38 Diamondback, as well as the standard blue for both the .38s and the remaining four-inch .22. From that point until 1977, the available variations remained the same.
In 1978, the six-inch blued .22 was added, with the blue four-inch .22 and the blue or nickel 2 inch and four-inch .38s remaining in the catalog. No six-inch .38 Diamondback was included.
This was an interesting year for Colt. Early on, the company announced that with the completion of the first production run of 1200 six-inch .22 Diamondbacks in October, the entire D-frame line of Colt revolvers would be permanently discontinued. This included not only the Diamondbacks, but such long-standard .38 Specials as the Agent, Cobra, Detective Special, Police Positive, and the newly designed Viper (see “Colt’s New Snake—The .38 Special Viper,” March 1978). The reasons for this move were due to marketing considerations and with the stresses being imposed on some of the lightweight two-inch .38 D frames due to increased police use of +P and ++P .38 Special ammunition (see “Gun Manufacturers Issue Ammo Warnings!” November 1978).
Before the year was out, however, Colt reevaluated its decision and determined not to drop the Diamondbacks or the Detective Special, and both remained in production in 1979. During that year, the Diamondbacks were available only in a blue four-inch .38 and a six-inch .22. No four-inch .22s were made that year. The nickel-finish option was permanently dropped, as was the 2 1/2-inch version of the .38 Diamondback. For 1980, the company added a six-inch .38 version, renewed the four-inch .22, and the present line of four- and six-inch blue Diamondback emerged. Company officials say this pattern of production will continue during the foreseeable future.
The actual production quantities of individual Diamondback variations during the gun’s somewhat checkered history could be determined only by an on-site examination of Colt records, ~ the 2 inch .22 style in particular relatively rare, and a quality specimen currently commands a healthy premium on the used-gun and collectors’ market
At present, the Diamondback is one of only three Colt .22s remaining in production the other 2 being the Trooper and the Ace and 1 of only 2 surviving D-frame models, the other being the Detective Special. Somebody once said Colt has discontinued more fine handguns than most companies ever produced.
By all accounts, the Diamondback is an extremely well-made and attractive gun, but the proof of a handgun’s worth is its accuracy, and so it was with considerable anticipation that I greeted the opportunity to run a thorough test on some current production specimens.
The mechanical features that most directly affect accuracy in a revolver are barrel/cylinder (B/C), gap, barrel/cylinder alignment, sight stability and trigger pull. Four & six inch .22 Diamondbacks were obtained for testing; both rated excellent on nearly all counts.
B/C gap in a .22 revolver should I a square-cut .006 inch, plus or minus 001 for minimum projectile upset as minimum pressure loss while the bullet is passing from cylinder to barrel. Both test Diamondbacks gauged exactly .006 inch.
Perfect B/C alignment requires that each chamber be exactly in line with the bore at the moment-of-fire, with a minimum of free rotational play in the cylinder. A check of both test guns with a .22-caliber range rod showed all chambers to be perfectly aligned, with absolutely no cylinder play at the moment of fire. This is due to one of Colt unique design features; full rearward pull of the trigger causes the cylinder to be held tightly against the cylinder stop by pressure from the cylinder rotation lever (hand).
Sight stability on both Diamondbacks was superb, with no slack or wobble in any direction, and positive recoil-proof locking at any windage or elevation setting.
The only area of mechanical engineering where the Diamondbacks did not earn a high rating was trigger pull. Single-action pull on the six-inch gun was a stiff 5.2 pounds; on the four incher, 4.75 pounds. Both broke clear exhibiting virtually no creep or over travel, but the pull was unduly heavy. Double-action pull on the six-incher freed at 7 pounds but “stacked” sharply at the last moment to a stiff 13 pounds, nearly doubling its weight. The four inch test gun freed at 8 pounds and stacked to 12 at letoff. Ideally. a DA revolver should have about a 3 pound SA pull and a 9 to 10 pound on a DA pull.
Heavy trigger pull is a well known characteristic of new out of the box DB’s, as has been universally noted by users of the guns, including gunwriters (See Skeeter Skelton’s story, “Colts Diamondback is Here to Stay!” March 1979). Actually, the DB’s trigger pull is not a great deal heavier than those of other current DA revolvers, but because the DB is a close twin to Colt’s superb Python, many shooters actually expect tit to feel like a Python’s pull. It doesn’t.
There are two main reasons why the Diamondback’s trigger pull is as heavy as it is. One is structural. Even though the Diamondback’s heft (34 ounces for the six-inch .22) qualifies it as a medium weight gun, most of that weight is in the barrel. The frame dimension which enclose the action are actually quite small (the smallest Colt makes) A small frame makes for small working parts, and small parts provide short moment-arms for leverage. And short moment-arms, as anyone familiar with mechanics knows, require more energy to operate. All other things being equal any small action revolver that the same design as a larger DA will have a heavier pull. The second reason is purely simple economics. Even though the Diamondback is well above average in terms of workmanship, styling, and finish, it is still a “standard-production” gun. Shooters who pick up a “Python-like Diamondback and do not find the Python-like smoothness and lightness in trigger pull should not be disappointed. They are forgetting that the Python unique in receiving special first-run tooling and handfitting in factory manufacture—which is why a Python cost about $150 more than an equivalent length Diamondback. And it certainly costs less than $150 to take a Diamondback to a good pistolsmith or to your own workbench and give it a tune-up that will make the trigger pull every bit as smooth and light as a Python.
The effect of trigger pull on an individual shooter’s accuracy with a particular gun is an entirely subjective matter. I know several people who have for years shot old, out-of-production six-guns that have the most ragged and stiff trigger pulls imaginable. Any of them can shoot rings around me with their gun simply because they know its feel. Because the guns I regularly shoot have all been tuned and timed, I shoot below par with any handgun that requires serious concentration to overcome a stiff trigger. As a result, when I took the sample Diamondbacks out to the test range, the group sizes were somewhat larger than they should be, given the inherent precision of the guns. With a variety of .22 - LR high-velocity ammunition fired at 25 yards from a sandbag rest, both the six- and four-inch guns averaged between 2.0 and 2.5 inches (see chart). The tightest group shot out of several dozen measured 1.5 inches.
This - accuracy is acceptable for recreational target shooting, plinking, and small-game hunting at close ranges, but it’s not sufficient for precision competition, where 25-yard group size should average less than 1.5 inches (the 10 ring on an NRA 25-yard slow-fire pistol target measures 1.6 inches).
At the same time, I knew the .22 Diamondback was capable of 1.0- to 1.5 inch accuracy because other shooters regularly got these results from their guns and because a few months previous, I had not had any difficulty getting 1.0 inch groups from another six-inch Diamondback .22 (see “The .22s— Rating All Your Favorite DA Revolvers,” June 1980). The trigger pull on that Diamondback, however, had been smoothed and lightened. For that reason, I was sure the large groups stemmed from my own difficulty with the stiffer trigger pulls, so I eliminated myself.
I put the six-inch test gun in a Ransom Machine Rest and fired a 25-yard group. It measured .75 inch. Clearly, the Diamondback has sufficient meXXXXXX
I like the Diamondbacks. They are extremely well-made, mechanically precise revolvers. The stiff factory-issue trigger does not unduly disturb me because it can be easily corrected (although I think Colt might still do a little better considering the fact that at a recommended retail price of $314.50, the six-inch Diamondback is the most expensive blue-steel .22 made in America).
But if you like the balance, styling, and performance of the Colt Python, you will like the Diamondback. Once you become comfortable with the trigger pull or smooth it up a bit, it will give you a lifetime of accuracy and service.

/forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.