Guns FAQ

Acanthus Scroll
An engraving design patterned after any of a variety of plants of the genus Acanthus, native to the Mediterranean, with large, segmented, thistle-like leaves

Automatic Colt Pistol. A proprietary designation for a type of rimless cartridge design, such as .45 ACP

The receiver of a gun containing the firing mechanism. The serially-numbered, legal soul of a firearm. Major types are: Boxlock, Sidelock, Blitz, and Bolt.

AE or Automatic Ejectors
fittings inset into the breech end of barrels of a break-open gun that kick out fired shells, while only raising unfired shells enough to be removed by hand

Alex Henry Forend
A groove at the forend tip, typical of this fine Scottish maker, (for tying a rifle into a vehicle-mounted rack?). Adopted by the traditionalist Bill Ruger for his single shot Model No. 1

As new in original box. Perhaps fired, but in virtually new condition

Anson Forend Release
A latch for securing the forend to the barrels of a break-open gun, operated, via a longitudinal rod, by a pushbutton exposed at the very tip of the forend. Typically seen on Purdey and Boss guns.

Antique Firearm
Defined according to Section 921 (a) (16), Title 18, U.S.C. as:

A. any firearm (including any firearm with matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898; and

B. any replica of any firearm described in subparagraph (A) if such replica (i) is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition, or (ii) uses rimfire or conventional centerfire fixed ammunition which is no longer manufactured in the United States and which is not readily available in the ordinary channels of commercial trade.

Articulated Front Trigger
A hinged front trigger, built to cushion its impact on one’s trigger finger as the gun recoils when the rear trigger is pulled.

Automatic Safety
A safety catch on a break-open gun that resets to the “safe” position each time the gun is opened, via a limb attached to the toplever spindle.

Bluing is a thin surface coloring, induced either by heat or by polishing and the repeated application of an acid solution to form a type of blue-black rust. Bluing reduces the reflectivity of polished steel parts and helps inhibit further rust. The percentage of original blue finish remaining is a quick indicator of the condition of a gun. In our condition descriptions, 98%blue means raw steel is showing through 2% of the overall blued surface. We try to describe the percentage of finish neither optimistically nor conservatively but exactly as it is.

Back Action
A sidelock action where the mainspring is mounted rearward towards the butt. The back action is often used in double rifles where the need for strength requires as little steel as possible be removed from the bar of the action

Enlarging the internal diameter of a shotgun barrel beyond its proper standard (.729″ in 12 gauge) by reaming, in an effort to reduce the recoil.

The portion of a break-open gun’s action extending forward from the bottom of the standing breech, supporting the hingepin. In modern side-by-side guns, it is usually machined to accept the cocking limbs and the main locking bolts as well.

Bar Action
A sidelock action where the mainspring is mounted forward into the bar of the action. Often more graceful in appearance than the back action.

Barrel Length
The length of a barrel as measured from the muzzle to the standing breech in a break-open gun or to the bolt face in a bolt-action rifle, including the chamber. A revolver barrel measurement does not include the cylinder, only the barrel itself.

Barrel Wall Thickness
The thickness of the walls of a shotgun barrel.

It is reasonable to assume that guns built by responsible manufacturers are safe to shoot, when new, with the loads for which they were intended. As the decades go by, however, as barrels are drawfiled or buffed for rebluing and as occasional pits are honed out of the bores, steel is gradually removed from the barrels. The barrel walls, already built thin for lightness, become thinner still. At some point they become too thin for safety. It is important to know the barrel wall thickness of an old, well-used shotgun before shooting it. A rule of thumb states that the minimum barrel wall thickness should be .020″ in a 12 gauge gun.


Beaded cheekpiece
A raised-carved cheek rest on the side of a buttstock, specifically with the extra detail of a shadow line around its perimeter where it blends into the buttstock proper.

A notch in a hammer or firing-pin housing. The sear rests in this notch when the firearm is cocked. When the trigger is pulled, the sear moves out of the bent, allowing the firing-pin to fall under the tension of the mainspring and fire the gun.

Bifurcated Lumps
A locking system for over & under guns whereby the barrels are mounted to the receiver via trunnions on either side of the lower barrel and where a pair of bolts move forward into recesses on either side of the barrel-set when the gun is closed. This system makes it possible to build an over & under gun with a sleeker, lower profile than possible when mounting the lumps, hook, and locking bites to the underside of the bottom barrel. Boss and Woodward over&under guns are built with bifurcated lumps. Browning and Merkel over&under guns are built with traditional lumps under the bottom barrel.

Blitz Action
A design where the moving parts of a break-open gun’s action are mounted to the trigger plate. Similar in construction to a Dickson Round Action. Often seen on German and Austrian guns. Identified externally by a broader-than-usual trigger plate

Bolt Action
An action type, most frequently used on rifles, perfected by Peter Paul Mauser in 1898, whereby a cylindrical shaft, controlled by an attached lever, manually feeds a cartridge into the chamber, turns down engaging locking lugs in recesses in the front receiver ring, allows firing by the fall of an internal spring-loaded pin, opening, extraction, recocking and ejection with the same lever in preparation for the next shot

Bolted Safety
A secondary catch on the safety, often seen on big-bore double rifles, designed to prevent its inadvertent disengagement by a careless gunbearer.

See Calibre, Gauge, Table

A type of action (receiver) for a break-open gun where the lockwork is contained within a box-shaped housing. (see also: Sidelock). A boxlock is superior to a sidelock because although more metal needs to be removed from the action body, less wood needs be removed from the head of the stock—and wood is generally more vulnerable than metal. The Anson & Deeley boxlock, patented in 1875, the simplest, most reliable and most successful action design, is identified by two pins spanning the width of the action, one at the bottom rear and one slightly forward and higher, upon which the sears and hammers, respectively, rotate.

Black powder express

The end of a barrel into which a cartridge is inserted.

A small secondary plate, mounted behind and parallel to a sidelock gun’s lockplate which supports the other end of the pins about which the moving parts rotate.

BT or Beavertail Forend
A broad forend, wrapping partially around the barrel(s) to give a more positive grip and to better protect the hand from hot barrels than does a splinter forend.

Bulino Engraving
Shallow, pictorial engraving designs, often of photographic quality, executed directly by hand onto the steel with a fine-pointed scribe called a burin, without the use of a chasing hammer. Also called banknote engraving. Often seen on high-grade, contemporary Italian shotguns

Bushed Firing Pins
Circular steel fittings, about 1/2 inch in diameter, screwed into the breech face of a gun and through which the firing pins pass. Firing pin bushings allow the convenient replacement of broken firing pins. They also allow the renewal of an older gun where, over the decades, leakage of high-pressure gas from corrosive primers has eroded the breech face around the firing pins. In British: Disk-set strikers.

The end of a gun stock; the part that rests on the shoulder when the gun is mounted

Cal. or Calibre
System of measurement for the internal bore diameter of a rifled-barreled firearm (rifle or pistol) based on the decimal part of an inch. For example, .25 calibre and .250 calibre both signify a bore size of 1/4 inch. American calibre designations refer to the distance from land to land, not groove to groove.

A general term referring to relatively short-barreled, quick-handling rifle. In Winchester lever-action terminology, a carbine has a single barrel-band.

A mark, typically stamped into the wood, especially of an American military rifle. It shows the initials of the name of the accepting inspector and often, the date he accepted the firearm into service.

Cast Off
An offset of a gun stock to the right, so that the line of sight aligns comfortably with the right eye while the butt of the stock rests comfortably on the right shoulder. Almost all right-handed shooters benefit from a little castoff and most custom built guns are made this way. The only question is how much. The castoff of a gun is about right when, with the gun comfortably mounted, the front bead lines up with the center of the standing breech. A stock offset to the left, for shooting from the left shoulder is said to be Cast On. See Eye Dominance.

CC or Casehardening Colors
mottled blue/green/brown colors on a shotgun or double rifle receiver, the by-product of a heat-treating process that incorporates carbon into the surface molecular structure of the steel, providing a hard-wearing surface without making the entire receiver brittle. The colors themselves are fairly perishable both from wear and from sunlight. The percentage of original case colors remaining is therefore a quick proxy for the cosmetic condition of the gun. Photo

Guns should never be rehardened in the vain interest of restoring the cosmetic effect of the colors. Casehardening is a heat process which alters the surface molecular structure of the steel. Rehardening an action can warp it. Subsequent efforts to straighten the metalwork, either by bending or filing can only harm the fine original metal-to-metal fit and adversely alter the workings of carefully aligned internal parts.

An area at the breech end of a barrel, of about the diameter of the cartridge for which the gun was intended, and into which the cartridge is inserted. The nominal length of a shotgun chamber will accommodate the loaded cartridge for which it was intended and allow for its crimp to open fully when the cartridge is fired. Although one can easily insert a longer-than-nominal-length loaded cartridge in a shotgun chamber, it is not advisable to do so because when it is fired the crimp will open into the forcing cone. Because of the taper of the forcing cone, the crimp will not be able to open fully and the gun will develop far greater pressure than it was designed to handle.

While most 12 gauge shotguns built today have nominal 2 3/4″ chambers, this was not always the case. Prewar American guns and many modern English guns often have shorter chambers. It is important to know the length of a gun’s chambers and to use the ammunition for which it was intended.

A regular pattern of fine grooves cut into the surface of a stock to aid in gripping a gun. Originally done for utility only, checkering has become an art form in itself; craftsmen adorning the borders with ribbons, fleur-de-lys, floral carving, etc. The amount of coverage, the precise regularity, and the number of lines per inch indicate the quality of the work. Too-fine checkering, however, defeats the purpose of the work altogether.

A carefully measured constriction of the bore of a shotgun at the muzzle, designed to control the spread of the shot as it leaves the barrel.

Hallowell & Co.’s descriptions of choke borings are determined by measuring with a bore micrometer, irrespective of any markings on the barrels. The internal diameter is measured four inches from the muzzle and again just at the muzzle. Subtracting gives the amount of constriction in thousandths of an inch.

In our descriptions of each gun, chokes are listed in the order of the normal sequence of firing.

Measurements of muzzle constriction by micrometer are useful to predict the pattern thrown by a shotgun barrel, but they remain merely a prediction. Patterns can vary depending on atmospheric pressure, humidity, length of cartridge, type of wad, size of shot, and numerous other factors. Terms such as “Improved Cylinder” and “Full” are only words, based on relative rules of thumb. The only way to determine the actual pattern thrown by a shotgun barrel is to shoot it, by convention at 40 yards, count the percentage of pellets falling within a 30″ circle placed around the visual center of the pattern, then do it a few more times and take an average.

Choke tubes
Short, interchangeable cylinders, of subtly different internal tapers, that screw into a threaded recess at the muzzle of a shotgun. By inserting different choke tubes, one can alter the shot pattern thrown by the gun. Choke tubes should be tightened until snug. Guns fitted for choke tubes should never be fired without tubes inserted.

Chopper-lump bbls (also called Demi-bloc barrels)
A method of joining the two separate tubes of a set of barrels where the right-hand half of the pair of lumps under the barrels are forged integrally with the right barrel and the left-hand half of the pair of lumps under the barrels are forged integrally with the left barrel. Chopper-lump barrels can be recognized by the fine joint-line running longitudinally down the center of each lump. This method of jointing barrels is the best because: 1. It is the strongest in relation to its weight, and 2. Because it allows the two barrels to be mounted closest to each other at the breech end, reducing problems regulating the points of aim of the two separate barrels

Claw Extractor
An essential design element of the Mauser 98 bolt action and its derivatives: the Springfield ’03 and the Winchester pre-’64 Model 70. A large, long extractor is mounted to and revolves around the bolt shaft, or more properly, remains stationary in the receiver raceway when the bolt revolves. This claw takes positive hold of the cartridge coming from the magazine and places it in the chamber when the bolt is closed. Then, when the bolt is opened, the claw, never having relinquished its grip on the rim of the cartridge, withdraws it from the chamber with absolute reliability.

Lesser bolt actions have a small clip built into the bolt face which snaps over the chambered cartridge rim when the bolt is closed. While cheaper to manufacture, this system allows the possibility of the clip slipping back off the rim of the expanded spent case during extraction. Most experienced hunters prefer an action with a Mauser-type claw extractor for its reliability, especially when facing dangerous game.

Claw Mounts
A quick-detachable scope mounting system, popular in Germany and Austria. The front of the scope is fitted with a hook-shaped tentacle which is inserted into a slot in a fixed front scope base. The rear of the scope is fitted with another set of hook-shaped tentacles. When these are pressed sharply downwards into their opposing receptacles they snap into place, held by a spring-loaded clasp, locking the scope into position. When properly installed, claw mounts are generally considered the best quick-detachable system for scope mounting: the cleanest looking, the easiest to operate and the most accurate in returning to zero. But, it is not an off-the-shelf, bolt-on system; claw mounts must be custom-fitted by a skilled gunsmith.

Cocking Indicators
Small devices attached to the internal hammers of a break-open gun and visible from the exterior of the gun to show when each barrel is cocked and when it has been fired. These are usually in the form of protruding pins on a boxlock gun or in the form of engraved or gold inlaid lines on the tumbler pins of a sidelock gun

The top of a gun’s stock, where one rests his cheek when mounting a gun. As it is the top of the stock that determines the position of one’s eye, and one’s eye is the rear sight on a shotgun, the position of the comb is very important in determining the proper fit of a shotgun.

Concealed Third Fastener
An extension protruding rearward from the breech end of a set of side-by-side barrels and entering a complementary recess in the breech face. The top of the extension is locked down by a cam attached to the toplever spindle. When the gun is closed this extra fastener is not visible from the exterior of the gun.

Cross Pin Fastener
A horizontal wedge, press-fit through the forend of a vintage gun, through a lump attached to the underside of the barrel and out the other side of the forend. To secure the forend in position. Also called a key fastener

Curios or Relics
– is defined in 27 CFR 178.11 as follows:

“Firearms which are of special interest to collectors by reason of some quality other than is associated with firearms intended for sporting use or as offensive or defensive weapons. To be recognized as curios or relics, firearms must fall within one of the following categories:

1. Firearms which were manufactured at least 50 years prior to the current date, but not including replicas thereof;
2. Firearms which are certified by the curator of a municipal, State, or Federal museum which exhibits firearms to be curios or relics of museum interest; and
3. Any other firearms which derive a substantial part of their monetary value from the fact that they are novel, rare, bizarre, or because of their association with some historical figure, period, or event. Proof of qualification of a particular firearm under this category may be established by evidence of present value and evidence that like firearms are not available except as collector’s items, or that the value of like firearms available in ordinary channels is substantially less.”

A list of acknowledged “Curios or Relics” is available from the Bureau of Alcohol, Tobacco and Firearms, Firearms Technology Branch, Room 6450, 650 Massachusetts Avenue NW, Washington, DC 20226.

A special Curios or Relics license is available from the BATF, which allows collectors to buy eligible firearms in interstate commerce. A licensed collector is not authorized to engage in business as a dealer in any firearms, including curios or relics.

DA or Double Action
An action type, typical on revolvers, where pulling the trigger through a long stroke revolves the cylinder, cocks the hammer and fires the gun—and alternatively, where manually cocking the hammer and then pulling the resulting single-stage trigger fires it also.

Damascus Bbls
Barrel tubes built up by twisting alternate strips of iron and steel around a fixed rod (mandrel) and welding them together in varying combinations according to the intended quality and the skill of the maker. The rod was withdrawn, the interior reamed and the exterior filed until the finished tube was achieved. Damascus barrels may be recognized by any of a variety of twist or spiral patterns visible in the surface of the steel. Before the 20th century, barrels were typically built in this manner because gunmakers did not have the technology to drill a deep hole the full length of a bar of steel without coming out the side.

Damascus barrels were usually intended for use with black powder—the standard of the day. The contour of the barrel wall thickness, intended for the fast explosion of black powder, was quite thick at the breech and tapered thinner towards the muzzle. It is not advisable to shoot modern smokeless powder in a damascus barrel. Apart from giving due deference to the age of such barrels and to the method of their construction, smokeless powder burns more slowly, lowering the pressure at the breech end, but considerably raising it further down the barrel to a level such barrels were rarely designed to handle.

Deeley Forend Release
A latch for securing the forend to the barrels of a break-open gun, operated by a short pull-down lever mounted to the center of the forend. Typically seen on Parker and Prussian Charles Daly guns.

Doll’s Head
A rib extension on a break-open gun, ending in a circular or semi-circular shape in plan (resembling the head of a doll), mating into a similarly-shaped recess in the top of the receiver, designed to resist the tendency of the barrels to pull away from the standing breech when firing. Because an action’s centerpoint of flexing when firing is at the base of the standing breech, not at the hingepin, a passive doll’s head extension makes an effective extra fastener, even without additional mechanical locks operated by the opening lever.

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