6mm Norma BR
Encyclopedia
The 6mm BR is a centerfire cartridge
created for benchrest shooting
. The cartridge is also known as the 6mm Bench Rest or simply 6 BR, and has also developed a following among varmint hunters because of its efficiency. There are two basic variants of very similar dimensions, known as the 6mm BR Remington and the 6mm Norma BR.
Since the cartridge was a wildcat and was not standardized until several years later, several variations of the cartridge existed. Cases required fire forming in the chamber to provide the maximum in accuracy as chambers of the rifles varied from one to another. Several 6mm BR variants exist apart from the Remington and Norma versions: the 6mm BRX, 6mm Dasher, 6 mm BRBS 6 mm UBL.
In 1978 Remington started manufacturing their Remington 40-X rifle in the 6mm BR and named their version of the cartridge the 6mm Bench Rest Remington. By 1988 Remington was also manufacturing ammunition. Remington continues to offer the 6mm BR Remington in the 40-X series rifles. The Remington version of this cartridge is now considered to be obsolete.
In 1996 Norma of Sweden introduced the 6mm Norma BR which was dimensionally similar to the 6mm BR Remington. However the chamber of the Norma version provided a longer throat making allowances for the seating of VLD bullets. This is the most common variation of the cartridge used today.
The 6mm Norma BR has become a popular chambering in match rifles used in 300 metres (328 yd) ISSF
and CISM
and other 300 metres rifle disciplines.
introduced by Norma
in 1996. It is based on the 6mm BR Remington cartridge, although where Remington's cartridge was intended for bullets of about 70 gr, Norma standardized their set of chambering specifications for a very low drag (VLD) bullet
of over 100 gr, thus realizing the long-range capabilities of the cartridge. This resulted in a much longer throat in rifles chambered for the Norma 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...
created for benchrest shooting
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...
. The cartridge is also known as the 6mm Bench Rest or simply 6 BR, and has also developed a following among varmint hunters because of its efficiency. There are two basic variants of very similar dimensions, known as the 6mm BR Remington and the 6mm Norma BR.
Cartridge History
Soon after the .308x1.5 Barnes cartridge introduction wildcatters and experimenters began developing their own wildcats based on the cartridge. By 1963 there were a several .22 (5.7 mm) and .24 (6.1 mm) caliber cartridges based on the Barnes’ cartridge. The new cartridges’ accuracy and efficiency was noticed by the bench rest shooting community. The .24 caliber (6.1 mm) cartridge version became known as the 6mm Bench Rest or the 6mm BR due to its widespread use in the sport of bench rest shooting.Since the cartridge was a wildcat and was not standardized until several years later, several variations of the cartridge existed. Cases required fire forming in the chamber to provide the maximum in accuracy as chambers of the rifles varied from one to another. Several 6mm BR variants exist apart from the Remington and Norma versions: the 6mm BRX, 6mm Dasher, 6 mm BRBS 6 mm UBL.
In 1978 Remington started manufacturing their Remington 40-X rifle in the 6mm BR and named their version of the cartridge the 6mm Bench Rest Remington. By 1988 Remington was also manufacturing ammunition. Remington continues to offer the 6mm BR Remington in the 40-X series rifles. The Remington version of this cartridge is now considered to be obsolete.
In 1996 Norma of Sweden introduced the 6mm Norma BR which was dimensionally similar to the 6mm BR Remington. However the chamber of the Norma version provided a longer throat making allowances for the seating of VLD bullets. This is the most common variation of the cartridge used today.
The 6mm Norma BR has become a popular chambering in match rifles used in 300 metres (328 yd) ISSF
ISSF shooting events
The International Shooting Sport Federation recognizes several shooting events, some of which have Olympic status. They are divided into four disciplines: rifle, pistol, shotgun and running target....
and CISM
International Military Sports Council
The International Military Sports Council or Conseil International du Sport Militaire , established 1948, is one of the largest multidisciplinary organisations in the world...
and other 300 metres rifle disciplines.
Design
The cartridge is based a necked down .308x1.5 inch Barnes cartridge which in turn is based on the Winchester case shortened to 1.5 inches (38.1 mm). It is one of the earlier cartridges to follow the short, fat design concept. Short fat cartridges have characteristics that make them more efficient and accurate.6mm Norma BR
The 6mm Norma BR cartridgeCartridge (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...
introduced by Norma
Norma (company)
Norma Precision is a Swedish manufacturer of ammunition located in Åmotfors, in the province of Värmland, just 20 km of the Norwegian border. It is commonly referred to as simply Norma.- History :...
in 1996. It is based on the 6mm BR Remington cartridge, although where Remington's cartridge was intended for bullets of about 70 gr, Norma standardized their set of chambering specifications for a very low drag (VLD) bullet
Very-low-drag bullet
Very-low-drag bullets are primarily a small arms ballistics development of the 1980s–1990s, driven by shooters' desire for bullets that will give a higher degree of accuracy and kinetic efficiency, especially at extended ranges. To achieve this the projectile must minimize air resistance in flight...
of over 100 gr, thus realizing the long-range capabilities of the cartridge. This resulted in a much longer throat in rifles chambered for the Norma cartridge.
External links
- 6mmBR.com - 6mm BR Rifle Shooting and Reloading Information
- 6mm BR Remington page at ChuckHawks.com