Misplaced Pages

#558441

68-586: Warren Center, working in his basement shop in the 1960s, developed a unique, break-action, single-shot pistol. In 1965, Center joined the K.W. Thompson Tool Company and they introduced this design as the Thompson-Center Contender in 1967. Although they cost more than some hunting revolvers, the flexibility of being able to shoot multiple calibers by simply changing the barrel and sights and its higher accuracy made it popular with handgun hunters. As K.W. Thompson Tool began marketing Center's Contender pistol,

136-453: A black oxide coating. It is named after the blue-black appearance of the resulting protective finish. Bluing involves an electrochemical conversion coating resulting from an oxidizing chemical reaction with iron on the surface selectively forming magnetite ( Fe 3 O 4 ), the black oxide of iron . In comparison, rust , the red oxide of iron ( Fe 2 O 3 ), undergoes an extremely large volume change upon hydration; as

204-614: A heeled bullet , which means that the bullet is the same diameter as the case, which has a narrower "heel" portion that fits into the case. It is one of the few cartridges that are manufactured and used in a large variety of rifles and handguns. Larger rimfire calibers were used during the American Civil War in the Henry repeating rifle , the Spencer repeating rifle , the Ballard Rifle , and

272-520: A sawmill in Kansas. Calibers available for the Contender were initially limited, stopping just short of the .308 Winchester -class rifle cartridges. However, almost any cartridge from .22 Long Rifle through .30-30 Winchester is acceptable, as long as a peak pressure of 48,000 CUP is not exceeded. This flexibility prompted a boom in the development of wildcat cartridges suitable for the Contender, such as

340-435: A G1 frame. Starting in 1967, the Contender was discontinued in 2000. The year of manufacture is determined by the serial numbers as follows: Rimfire ammunition A rim-fire (or rimfire ) is a type of metallic cartridge used in firearms where the primer is located within a hollow circumferential rim protruding from the base of its casing . When fired, the gun's firing pin will strike and crush

408-480: A blued finish. This finish allows them to be stored in high-moisture conditions, like sports bags, without rusting. Bluing is often a hobbyist endeavor, and there are many methods of bluing, and continuing debates about the relative efficacy of each method. Historically, razor blades were often blued steel. A non-linear resistance property of the blued steel of razor blades, foreshadowing the same property later discovered in semiconductor diode junctions, along with

476-415: A chemical conversion coating, is not as robust against wear and corrosion resistance as plated coatings, and is typically no thicker than 2.5 micrometres (0.0001 inches). For this reason, it is considered not to add any appreciable thickness to precisely-machined parts. Friction, as from holster wear, quickly removes cold bluing, and also removes hot bluing, rust, or fume bluing over long periods of use. It

544-401: A conical bullet. According to Berkeley R. Lewis, a firearms historian, this later Smith & Wesson cartridge was 'essentially the same as Houllier's 1846 patent'. This led to the .22 Long in 1871, with the same bullet weight as the short but with a longer case and 5 gr (0.32 g) of black powder. This was followed by the .22 Extra Long in 1880, with a longer case and heavier bullet than

612-470: A dedicated shooting parlor or shooting gallery. 6mm Flobert Parlor pistols came into fashion in the mid-19th century; they typically featured heavy barrels. This cartridge was improved upon by Benjamin Houllier in 1846. The next rimfire cartridge was the .22 Short, developed for Smith & Wesson 's first revolver , in 1857; it used a longer rimfire case and 4 gr (0.26 g) of black powder to fire

680-401: A different barrel and pre-aligned sights. This allowed easy changes of calibers, sights, and barrel lengths, with only a flat screwdriver being required for this change. The Contender frame has two firing pins, and a selector on the exposed hammer, to allow the shooter to choose between rimfire or centerfire firing pins, or to select a safety position from which neither firing pin can strike

748-445: A furnace, for example for a sword or other item traditionally made by a blacksmith or specialist such as a weapon-smith. Blacksmith products to this day may occasionally be found made from blued steel by traditional craftsmen in cultures and segments of society who use that technology either by necessity or choice. Bluing may be applied by immersing steel parts in a solution of potassium nitrate , sodium hydroxide , and water heated to

SECTION 10

#1732869653559

816-457: A gun's finish, to prevent a small scratch from becoming a major source of rust on a gun over time. Cold bluing is not particularly resistant to holster wear, nor does it provide a large degree of rust resistance. Often it does provide an adequate cosmetic touch-up of a gun's finish when applied and additionally oiled on a regular basis. However, rust bluing small areas often match, blend, and wear better than any cold bluing process. At least one of

884-538: A hot bath (although at a lower temperature) chemically induced method, it is possible through controlling the temperature to heat steel precisely such as to cause the formation of black oxide selectively over the red oxide. It, too, must be oiled to provide any significant rust resistance. There are also methods of cold bluing, which do not require heat. Commercial products are widely sold in small bottles for cold bluing firearms, and these products are primarily used by individual gun owners for implementing small touch-ups to

952-406: A more protective, stable coating than the red oxide; the boiling water also removes any remaining residue from the applied acid solution (often nitric acid and hydrochloric acid diluted in water). The loose oxide was then carded (scrubbed) off, using a carding brush – a wire brush with soft, thin (usually about 0.002 in (0.051 mm) thick) wires – or wheel. This process was repeated until

1020-415: A plastic capsule. Shotshells will not feed reliably in some magazine-fed firearms, because of the unusual shape of some cartridges that are crimped closed at the case mouth, and the relatively fragile plastic tips of other designs. Shotshells will not produce sufficient power to cycle semiautomatic actions, because, unlike projectile ammunition, nothing forms to the lands and grooves of the barrel to create

1088-417: A primer. The initial baseline design of the Contender had no central safe position on the hammer, having only centerfire and rimfire firing pin positions, each being selectable through using a screwdriver. Three variants of the original Contender design were later developed, distinguished easily by the hammer design. The first variant has a push button selector on the hammer for choosing rimfire vs. centerfire,

1156-523: A rare but modern 9 mm Flobert Rimfire among hunters in Europe is the 1 + 3 ⁄ 4  in (44 mm) brass shotshell manufactured by Fiocchi in Lecco, Italy, using a .25 oz (7.1 g) shot of No. 8 shot with a velocity of 600 ft/s (180 m/s). Bluing (steel) Bluing , sometimes spelled as blueing , is a passivation process in which steel is partially protected against rust using

1224-409: A reasonably airtight crucible in a mixture of charred leather, bone charcoal and wood charcoal. This crucible was heated to 730 °C (1,350 °F) for up to 6 hours (the longer the heat was applied the thicker the case hardening). At the end of this heating process the crucible is removed from the oven and positioned over a bath of water with air forced through a perforated coil in the bottom of

1292-476: A result, the oxide easily flakes off, causing the typical reddish rusting away of iron. Black oxide provides minimal protection against corrosion, unless also treated with a water-displacing oil to reduce wetting and galvanic action. In colloquial use, thin coatings of black oxide are often termed 'gun bluing', while heavier coatings are termed 'black oxide'. Both refer to the same chemical process for providing true gun bluing. Various processes are used to produce

1360-422: A serial number greater than 195 000 . The earliest barrels, from early 1967 to late 1967, were all octagonal with a flat bottom lug, and were available in only 10 and 8 + 3 ⁄ 4 inches (250 and 220 mm) lengths. The next group of barrels, from late 1967 to 1972, were available in 6,  8 + 3 ⁄ 4 and 10 inches (150, 220 and 250 mm) lengths. Later, round barrels were added in

1428-409: A vinegar soak, for the rusting step to avoid the need for more dangerous acids. Fume bluing is another process similar to rust bluing. Instead of applying the acid solution directly to the metal parts, the parts are placed in a sealed cabinet with a moisture source, a container of nitric acid and a container of hydrochloric acid . The mixed fumes of the acids produce a uniform rust on the surface of

SECTION 20

#1732869653559

1496-471: A wider variety of lengths, including 10, 12 and 14 inches (250, 300 and 360 mm). Likewise, round barrels in heavier (bull) barrel configurations, known as Super 14 pistol and Super 16 pistol barrels, respectively, were added. Carbine barrels in 16 and 21 in (410 and 530 mm) were added for the Contenders. Sights on all the pistol barrels have varied, ranging from low iron sights, only, in

1564-619: Is also used for providing coloring for steel parts of fine clocks and other fine metalwork. This is often achieved without chemicals by simply heating the steel until a blue oxide film appears. The blue appearance of the oxide film is also used as an indication of temperature when tempering carbon steel after hardening, indicating a state of temper suitable for springs. Bluing is also used in seasoning carbon steel cookware, to render it relatively rust-proof and non-stick. In this case cooking oil, rather than gun oil, acts to displace water and prevent rust. Premium fencing blades are often offered with

1632-577: Is also useful for shooting birds inside storage buildings as it will not penetrate walls or ceilings. At a distance of about 10 ft (3.0 m), which is about the maximum effective range, the pattern is about 8 in (200 mm) in diameter from a standard rifle. Special smoothbore shotguns, such as the Marlin Model 25MG "Garden Gun" can produce effective patterns out to 15 to 20 yd (14 to 18 m) using .22 WMR shotshells, which hold .125 oz (3.5 g) of No. 11 or No. 12 shot contained in

1700-461: Is called 'peacock blue', a rich iridescent blue. Color case hardening is the predecessor of all metal coloring typically employed in the firearms industry. Contemporary heat-treatable steels did not exist or were in their infancy. Soft, low-carbon steel was used, but strong materials were needed for the receivers of firearms. Initially case hardening was used but did not offer any aesthetics. Colour case hardening occurs when soft steels were packed in

1768-433: Is extracted when the mechanism is opened. Barrels have been made available in either blued or stainless configurations, to match the finish available on Contender receivers. Unlike most other firearm actions , the break-action design does not require the barrels to be specially fitted to an individual action. Any barrel, with the exception of a Herrett barrel, that is made for a Contender will fit onto any frame, allowing

1836-482: Is typically done at an elevated temperature, 135 to 155 °C (275 to 311 °F). This method was adopted by larger firearm companies for large scale, more economical bluing. It does provide good rust resistance, which is improved with oil. "Rust bluing" and "fume bluing" provide the best rust and corrosion resistance as the process continually converts any metal that is capable of rusting into magnetite ( Fe 3 O 4 ). Treating with an oiled coating enhances

1904-508: Is usually inadvisable to use cold bluing as a touch-up where friction is present. If cold bluing is the only practical option, the area should be kept oiled to extend the life of the coating as much as possible. New guns are typically available in blued finish options offered as the least-expensive finish, and this finish is also the least effective at providing rust resistance, relative to other finishes such as Parkerizing or hard chrome plating or nitriding processes like Tenifer . Bluing

1972-464: The .17 WSM uses the blank case from a .27 caliber nail gun that is necked down to accommodate a .17 caliber bullet, resulting in a much higher muzzle velocity and energy than the .17 HMR . Some .22 caliber rimfire cartridges are loaded with a small amount of No. 11 or No. 12 shot (about .067 oz (1.9 g)). This " snake shot " is only marginally effective in close ranges, and is usually used for shooting snakes, rats or other small animals. It

2040-411: The .45 Colt /.410 barrel or through a special 21-inch (530 mm) smoothbore shotgun barrel. A ported, rifled, .44 Magnum barrel was made available for use with shotshell cartridges in a removable-choke .44 Magnum barrel, with the choke being used to unspin the shot from the barrel rifling, or, by removing the choke, for use with standard .44 Magnum cartridges. The degree of flexibility provided by

2108-417: The 7-30 Waters and .357 Herrett and the various TCU cartridges , most of which were commonly based on either the widely available .30-30 Winchester or .223 Remington cases. The largest factory caliber offered for the Contender was the .45-70 , which, although a much larger case than the .308, is still feasible because of the relatively low cartridge pressures of the original black-powder round relative to

Thompson/Center Contender - Misplaced Pages Continue

2176-620: The Frank Wesson carbine . While rimfire cartridges larger than .22 caliber existed, such as the .30 rimfire, .32 rimfire , .38 rimfire , .41 Short (for the Remington Model 95 derringer), .44 Henry (for the Henry rifle, later used by the famous Winchester Model 1866 ), the .56-56 Spencer (for the Spencer rifle was the world's first military metallic cartridge repeating rifle), all the way up to

2244-425: The firing pin strikes and crushes the base's rim to ignite the primer. The rim of such a cartridge is essentially an expanded and flattened end section of the case, and the priming compound is filled from inside into the trough cavity inside the rim. The case is then filled with propellant ( gunpowder ) and sealed off by the projectile ( bullet ). Rimfire cartridges are limited to low chamber pressures because

2312-400: The production cost of the case material and powder load are both low, and the manufacturing process is significantly more streamlined than that for centerfire cartridges (which require more steps in the assembly process). As a result, rimfire cartridges are typically very affordable, primarily because of the inherent cost-efficiency of manufacturing in large lots , which has contributed to

2380-445: The .22 Long. American firearms manufacturer J. Stevens Arms & Tool Company introduced the .22 Long Rifle cartridge in 1887. It combined the casing of the .22 Long with the 40-grain (2.6 g) bullet of the .22 Extra Long , giving it a longer overall length, a higher muzzle velocity, and superior performance as a hunting and target round, rendering the .22 Short, .22 Long, and .22 Extra Long cartridges obsolete. The .22 LR uses

2448-530: The .58 Miller, they were quickly made obsolete by the newly developed centerfire cartridges. The early 21st century has seen a revival in .17 caliber (4.5 mm) rimfire cartridges. New and increasingly popular, the 17 HMR is based on a .22 WMR casing with a smaller formed neck which accepts a .17 bullet. The advantages of the 17 HMR over .22 WMR and other rimfire cartridges are its much flatter trajectory and its highly frangible hollow point bullets (often manufactured with plastic "ballistic tips" that improve

2516-465: The Contender design is unique for experimenting with new cartridges, handloads , barrel lengths, and shotshells. The original Contender is now known as the generation one (G1) Contender and was replaced by the G2 Contender in 1998. The new design is dimensionally the same as the original Contender, but uses an Encore-style trigger group. Due to the changes in the trigger mechanism, and to differences in

2584-583: The angle of the grip relative to the boreline of the gun, the buttstocks and pistol grips are different between the G1 and G2 Contenders and will not interchange. The G2 uses essentially the same barrels and fore-ends as the original Contender and barrels will interchange, with the only two exceptions being the G2 muzzleloading barrels, which will only fit the G2 frame, and the Herrett barrels/fore-ends, which are specific for use only on

2652-446: The bath. The bottom of the crucible is opened allowing the contents to drop into the rapidly bubbling water. The differential cooling causes patterns of colors to appear as well as hardening the part. Different colors can be achieved through variations of this method including quenching in oil instead of water. 'Browning' is controlled red rust Fe 2 O 3 , and is also known as 'pluming' or 'plum brown'. One can generally use

2720-477: The boiling point, 275–310 °F (135–154 °C) depending on the recipe. Similarly, stainless steel parts may be immersed in a mixture of nitrates and chromates, similarly heated. Either of these two methods is called 'hot bluing'. Hot bluing is the current standard in gun bluing, as both it and rust bluing provide the most permanent degree of rust-resistance and cosmetic protection of exposed gun metal, and hot bluing takes less time than rust bluing. Rust bluing

2788-418: The bullet's external ballistics ). The .17 HM2 (Hornady Mach 2) is based on the .22 Long Rifle and offers similar performance advantages over its parent cartridge, at a significantly higher cost. While .17 HM2 sells for about four times the cost of .22 Long Rifle ammunition, it is still significantly cheaper than most centerfire ammunition and somewhat cheaper than the .17 HMR. First shown at the 2013 SHOT Show,

Thompson/Center Contender - Misplaced Pages Continue

2856-416: The case must be thin enough to allow the firing pin to crush the rim and ignite the primer. Rimfire cartridges of up to .58 caliber were once common when black powder was used as a propellant. Modern rimfire cartridges use smokeless powder , which generates much higher pressures and tend to be of .22 caliber (5.5 mm) or smaller. This also means that rimfire firearms can be very light and inexpensive, as

2924-440: The cold bluing solutions contains selenium dioxide . These work by depositing a coating of copper selenide on the surface. In the nitre bluing process, polished and cleaned steel parts are immersed in a bath of molten salts—typically potassium nitrate and sodium nitrate (sometimes with 9.4 grams (0.33 oz) of manganese dioxide per pound of total nitrate). The mixture is heated to 310 to 321 °C (590 to 610 °F) and

2992-408: The company name was changed to Thompson/Center Arms Company. Originally the chamberings were on the low end of the recoil spectrum such as .22 LR , .22 WMR , .22 Hornet , .38 Special , and .22 Remington Jet , but as Magnum calibers took off in the 1970s, the Contender quickly became very popular with shooting enthusiasts. The most unusual feature of the Contender is how the barrel is attached to

3060-431: The continuing market popularity of these small-caliber cartridges. Frenchman Louis-Nicolas Flobert invented the first rimfire metallic cartridge in 1845. The 6mm Flobert cartridge consisted of a percussion cap with a bullet attached to the top. These cartridges do not contain any powder, the only propellant substance contained in the cartridge is the percussion cap. In Europe, the .22 BB Cap (introduced in 1845) and

3128-427: The cosmetic appearance of and provide a measure of corrosion resistance to their firearms. It is also used by machinists, to protect and beautify tools made for their own use. Bluing also helps to maintain the metal finish by resisting superficial scratching, and also helps to reduce glare to the eyes of the shooter when looking down the barrel of the gun. All blued parts still require oiling to prevent rust. Bluing, being

3196-415: The desired depth of color was achieved or the metal simply did not color further. This is one of the reasons rust and fume bluing are generally more rust-resistant than other methods. The parts are then oiled and allowed to stand overnight. This process leaves a deep blue-black finish. Modern home hobbyist versions of this process typically use a hydrogen peroxide and salt solution, sometimes preceded with

3264-400: The earlier years to a choice of either low or high iron sights, as well as no sights, for those pistol barrels intended for use with a scope. Various barrels have sometimes included ejectors as well as extractors, or extractors only, as well as containing either a flat bottom lug, a stepped bottom lug, or split bottom lugs. On barrels with an extractor only, about a quarter of the empty cartridge

3332-408: The early 19th century, such as teat-fire and pinfire , only small caliber rimfire ( .22   caliber (5.6   mm) or less) cartridges have survived to the present day with regular use. The .22   Long Rifle rimfire cartridge, introduced in 1887, is by far the most common ammunition found in the world today in terms of units manufactured and sold. Rimfire ammunition is so named because

3400-405: The frame. By removing the fore-end, a large hinge pin is exposed; by pushing this hinge pin out, the barrel can be removed. Since the sights and extractor remain attached to the barrel in the Contender design, the frame itself contains no cartridge-specific features. A barrel of another caliber or length can be installed and pinned in place, the fore-end replaced, and the pistol is ready to shoot with

3468-483: The hammer only in the safety (center) position. Barrels have been made in lengths of 6,  8 + 3 ⁄ 4 , 10, 12, 14, 16, 21 and 24 inches (150, 220, 250, 300, 360, 410, 530 and 610 mm). Heavier recoiling cartridge barrels have been made with integral muzzle brakes . Barrels for the original Contender may be used on the later-released G2 Contender and G2 barrels may be used on original Contender frames with

SECTION 50

#1732869653559

3536-422: The limits of the bolt face of the Contender receiver. Custom gunmakers have added to the selection, such as the J. D. Jones line of JDJ cartridges based on the .225 Winchester and .444 Marlin . Other barrel makers pushed beyond the limits the factory set, and chambered Contender barrels in lighter .308-class cartridges like the .243 Winchester . The Contender can fire .410 bore shotgun shells , either through

3604-442: The oxide coating. "Cold" bluing is generally a selenium dioxide -based compound that colours steel black, or more often a very dark grey. It is a difficult product to apply evenly, offers minimal protection and is generally best used for small fast repair jobs and touch-ups. The "hot" process is an alkali salt solution using potassium nitrite or sodium nitrate and sodium hydroxide, referred to as "traditional caustic black", that

3672-405: The parts (inside and out) in about 12 hours. The parts are then boiled in distilled water, blown dry, then carded, as with rust bluing. These processes were later abandoned by major firearm manufacturers as it often took parts days to finish completely, and was very labor-intensive. They are still sometimes used by gunsmiths to obtain an authentic finish for a period gun of the time that rust bluing

3740-546: The parts are suspended in this solution with wire. The parts must be observed constantly for colour change. The cross section and size of parts affect the outcome of the finish and time it takes to achieve. This method must not be used on critically heat-treated parts such as receivers, slides or springs. It is generally employed on smaller parts such as pins, screws, sights, etc. The colours range through straw, gold, brown, purple, blue, teal, then black. Examples of this finish are common on older pocket watches whose hands exhibit what

3808-510: The pistol while hunting to a "hair trigger" suitable for long range target shooting (see accurize ). Unlike the later G2 Contender, the original Contender may be safely dry-fired (provided the hammer is not drawn back from the second notch) to allow a shooter to become familiar with the trigger pull. The break-action only has to be cycled, while leaving the hammer in the second notch position, to practice dry-firing. G2's with switchable firing pins (centerfire or rimfire) can be safely dry-fired with

3876-510: The pressure necessary to cycle the firearm's action. The 9 mm Flobert is a notable rimfire cartridge that is still in production in Europe and is chambered by the Winchester Model 36 in the 1920s. This cartridge is primarily loaded with a small amount of shot, but can also fire a small ball, and is used in " garden gun ", which are miniature shotguns. Its power and range are very limited, making it suitable only for pest control. An example of

3944-432: The protection offered by the bluing. This process is also the only process safely used to re-blue vintage shotguns. Many double-barreled shotguns are soft soldered (lead) or silver brazed together and many of the parts are attached by that method also. The higher temperatures of the other processes as well as their caustic nature could weaken the soldered joints and make the gun hazardous to use. Bluing can also be done in

4012-456: The ready availability of blued steel razor blades, led to the use of razor blades as a detector in crystal set AM radios that were built by servicemen (as foxhole radios ) or by prisoners of war during World War II. Bluing only works on ferrous materials, such as steel or cast iron, for protecting against corrosion because it changes iron into Fe 3 O 4 . As aluminium and polymers do not rust, they cannot be blued, and no corrosion protection

4080-452: The rim against the edge of the barrel breech, sparking the primer compound within the rim, and in turn ignite the propellant within the case. Invented in 1845 by Louis-Nicolas Flobert , the first rimfire metallic cartridge was the .22 BB Cap (also known as the 6   mm Flobert) cartridge, which consisted of a percussion cap with a bullet attached to the top. While many other different cartridge priming methods have been tried since

4148-423: The round versus the bull barrels. The fore-ends have had an assortment of either one or two screw attachment points, used for attaching the fore-ends to the barrel with its matching one or two attachment points. Universally, the fore-ends, in addition to attaching to the barrel, cover the single hinge pin that connects the barrel to the receiver. The wood stocks and forend are made specifically for Thompson Center by

SECTION 60

#1732869653559

4216-447: The same solution to brown as to blue. The difference is immersion in boiling water for bluing. The rust then turns to black-blue Fe 3 O 4 . Many older browning and bluing formulas are based on corrosive solutions (necessary to cause metal to rust), and often contain cyanide or mercury salts solutions that are especially toxic to humans. Bluing is most commonly used by gun manufacturers, gunsmiths , and gun owners to improve

4284-442: The second variant has a left-center-right toggle switch for selecting center fire-safe-rimfire firing pins, and the third variant has a horizontal bolt selection for choosing center fire-safe-rimfire firing pin positions. All three of these Contender variants have a cougar etched on the sides of the receiver, thereby easily distinguishing them from the later G2 Contender which has a smooth-sided receiver without an etched cougar. Some of

4352-410: The shooter to purchase additional barrels in different calibers for a fraction of the cost of a complete firearm. Since the sights are mounted on the barrel, they remain sighted-in and zeroed between barrel changes. Pistol grips, butt stocks and fore-ends have been made available in stained walnut, or in recoil reducing composite materials. Different pistol fore-ends are required for the octagonal versus

4420-403: The slightly more powerful .22 CB Cap (introduced in 1888) are both called 6mm Flobert and are considered the same cartridge. These cartridges have a relatively low muzzle velocity of around 600 ft/s (183 m/s) to 800 ft/s (244 m/s). Flobert also made what he called " parlor guns " for this cartridge, as these rifles and pistols were designed for target shooting in homes with

4488-412: The very earliest Contenders, those requiring a screwdriver to switch the firing pin between rimfire and centerfire, had smooth sides, without the cougar etched on the sides. The original Contender designs have an adjustable trigger, allowing the shooter to change both take-up and overtravel, permitting user selection of a range of trigger pulls ranging from a fairly heavy trigger pull suitable for carrying

4556-408: Was developed between hot and cold bluing processes, and was originally used by gunsmiths in the 19th century to blue firearms prior to the development of hot bluing processes. The process was to coat the gun parts in an acid solution, let the parts rust uniformly, then immerse the parts in boiling water to convert the red oxide Fe 2 O 3 to black oxide Fe 3 O 4 , which forms

4624-416: Was in vogue, analogous to the use of browning on earlier representative firearm replicas. Rust bluing is also used on shotgun barrels that are soldered to the rib between the barrels, as hot bluing solutions melt the solder during the bluing process. Large scale industrial hot bluing is often performed using a bluing furnace. This is an alternative method for creating the black oxide coating. In place of using

#558441