Chamber reamer
Encyclopedia
A chamber reamer is a specific type of fluted reamer
used by gunsmith
s and firearm
s manufacturers to cut the chamber of a handgun
, rifle
, or shotgun
. The chamber reamer is inserted into the bore of a barrel and held stationary while the barrel is turned around it (typically by means of a lathe
). The reamer slowly cuts away material, leaving a chamber capable of accepting a specific cartridge
.
Chamber reamers come in two general types - solid pilot reamers and floating pilot reamers. A solid pilot reamer has, as the name suggests, a solid steel
pilot on the end to guide the reamer through the bore of the barrel. These reamers are generally more durable and less expensive than floating pilot reamers. Floating pilot reamers use interchangeable pilots that are positioned at the front of the reamer. The primary advantage of a floating pilot reamer is that it is self-centering and can be fitted with a pilot that is an exact match with the barrel it is passing though. Barrels tend to vary in diameter by minute amounts, and this variation can create a situation whereby the solid pilot reamer fits too loosely or too snugly in the bore. Another advantage of floating pilot reamers is that the pilot itself does not spin with the reamer, and therefore is less likely to damage the bore. The primary disadvantage of the floating point reamer is that the nose of the reamer must be cut down in diameter
to accommodate the reamer pilot, resulting in a more delicate reamer.
Chamber reamers are typically made of high speed steel
and require lubrication
during the cutting operation. A chamber reamer, regardless of pilot design, will operate most efficiently at speed of 200 to 300 RPM, and feed rate just fast enough to avoid chatter. Chamber reamers are designed with flutes to collect and extract the cut material, however these flutes must be periodically cleaned (typically after every .2" of cutting). Finally, reamers must be sharpened from time to time. Given proper care, a reamer can cut 10-15 chambers between sharpening.
Manufacturers produce most chamber reamers to SAAMI
specifications so that any factory ammunition
can be safely used in any firearm
chambered with their reamer, for a given cartridge. Most reamer manufacturers will, however, produce reamers to customer specifications. These are useful to benchrest shooter
who are willing to trade off compatibility for accuracy, and by 'wildcatters
' - individuals who are interested in designing completely new cartridges.
Reamer
A reamer is a metalworking tool used to create an accurate sized hole. The process is called reaming. They may be used as a hand tool or in a machine tool, such as a milling machine or drill press.-Construction:...
used by gunsmith
Gunsmith
A gunsmith is a person who repairs, modifies, designs, or builds firearms. This occupation is different from an armorer. The armorer primarily maintains weapons and limited repairs involving parts replacement and possibly work involving accurization...
s and firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...
s manufacturers to cut the chamber of a handgun
Handgun
A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns ....
, rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
, or shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...
. The chamber reamer is inserted into the bore of a barrel and held stationary while the barrel is turned around it (typically by means of a lathe
Lathe
A lathe is a machine tool which rotates the workpiece on its axis to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation.Lathes are used in woodturning,...
). The reamer slowly cuts away material, leaving a chamber capable of accepting a specific cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...
.
Chamber reamers come in two general types - solid pilot reamers and floating pilot reamers. A solid pilot reamer has, as the name suggests, a solid steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
pilot on the end to guide the reamer through the bore of the barrel. These reamers are generally more durable and less expensive than floating pilot reamers. Floating pilot reamers use interchangeable pilots that are positioned at the front of the reamer. The primary advantage of a floating pilot reamer is that it is self-centering and can be fitted with a pilot that is an exact match with the barrel it is passing though. Barrels tend to vary in diameter by minute amounts, and this variation can create a situation whereby the solid pilot reamer fits too loosely or too snugly in the bore. Another advantage of floating pilot reamers is that the pilot itself does not spin with the reamer, and therefore is less likely to damage the bore. The primary disadvantage of the floating point reamer is that the nose of the reamer must be cut down in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
to accommodate the reamer pilot, resulting in a more delicate reamer.
Chamber reamers are typically made of high speed steel
High speed steel
High speed steelMost copyeditors today would tend to choose to style the unit adjective high-speed with a hyphen, rendering the full term as high-speed steel, and this styling is not uncommon . However, it is true that in the metalworking industries the styling high speed steel is long-established...
and require lubrication
Lubrication
Lubrication is the process, or technique employed to reduce wear of one or both surfaces in close proximity, and moving relative to each another, by interposing a substance called lubricant between the surfaces to carry or to help carry the load between the opposing surfaces. The interposed...
during the cutting operation. A chamber reamer, regardless of pilot design, will operate most efficiently at speed of 200 to 300 RPM, and feed rate just fast enough to avoid chatter. Chamber reamers are designed with flutes to collect and extract the cut material, however these flutes must be periodically cleaned (typically after every .2" of cutting). Finally, reamers must be sharpened from time to time. Given proper care, a reamer can cut 10-15 chambers between sharpening.
Manufacturers produce most chamber reamers to SAAMI
Sporting Arms and Ammunition Manufacturers' Institute
The Sporting Arms and Ammunition Manufacturers' Institute is an association of American firearms and ammunition manufacturers...
specifications so that any factory ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
can be safely used in any firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...
chambered with their reamer, for a given cartridge. Most reamer manufacturers will, however, produce reamers to customer specifications. These are useful to benchrest shooter
Benchrest shooting
Benchrest shooting is a sport in which very accurate and precise rifles are shot at paper targets from a rest or bench from a sitting position. Benchrest shooters are notoriously detail-oriented and constantly trying to further the accuracy potential of the rifle through experimentation. Nearly...
who are willing to trade off compatibility for accuracy, and by 'wildcatters
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...
' - individuals who are interested in designing completely new cartridges.