6mm BR

US rifle cartridge for benchrest shooting

6mm BR Remington

6mm BR, 6mm Dasher and .308 Winchester cartridges

Type| Rifle
Place of origin| United States
Production history
Designer| Wildcats: Various
Commercial: Mike Walker
Designed| Wildcats: 1962-1963
Commercial: 1978
Produced| 1978–present
Variants| Several. See article.
Specifications
Parent case| .308 Winchester
Case type| Rimless, Bottleneck
Bullet diameter| .243 in (6.2 mm)
Neck diameter| .270 in (6.9 mm)
Shoulder diameter| .458 in (11.6 mm)
Base diameter| .473 in (12.0 mm)
Case length| 1.560 in (39.6 mm)
Primer type| small rifle
Maximum CUP| 52,000 CUP
6mm Norma BR

Type| Rifle
Place of origin| Sweden
Production history
Manufacturer| Norma
Produced| 1996
Specifications
Parent case| 6mm BR Remington
Case type| Semi-rimmed, Bottleneck
Bullet diameter| 0.243 in (6.2 mm)
Land diameter| 0.236 in (6.0 mm)
Neck diameter| 0.271 in (6.9 mm)
Shoulder diameter| 0.458 in (11.6 mm)
Base diameter| 0.469 in (11.9 mm)
Rim diameter| 0.473 in (12.0 mm)
Rim thickness| 0.054 in (1.4 mm)
Case length| 1.560 in (39.6 mm)
Overall length| 2.440 in (62.0 mm)
Case capacity| 38-39.5 gr (2.45-2.55 ml)[1]
Ballistic performance
| Bullet mass/type | Velocity | Energy

|
|

6.8 g (105 gr) Lapua GB542 Scenar-L (OTM) | 815 m/s (2,670 ft/s) | 2,258 J (1,665 ft⋅lbf)
6.8 g (105 gr) Lapua Scenar (OTM) | 850 m/s (2,800 ft/s) | 2,457 J (1,812 ft⋅lbf)
5.8 g (90 gr) Lapua GB543 Scenar-L (OTM) | 900 m/s (3,000 ft/s) | 2,349 J (1,733 ft⋅lbf)
Test barrel length: 670mm
Source(s): [2][3][4]

The 6mm BR / 6.2x39mm 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.[5] There are two basic variants of very similar dimensions, known as the 6mm BR Remington and the 6mm Norma BR.

## Cartridge history

[edit]

Soon after the introduction of the .308 Winchester-based wildcat .308×1.5" Barnes cartridge, wildcatters and experimenters began developing their own wildcats based on .308 Winchester. By 1963 there were several .22 (5.56 mm) and .24 (6 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 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.

Because 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 as chambers of the rifles varied from one to another.[6] Several 6mm BR variants exist apart from the Remington and Norma versions: the 6mm BRX,[7] 6mm Dasher,[8] 6 mm BRBS[9] 6 mm UBL.[10]

### 6mm BR Remington

[edit]

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.[11] By 1988 Remington was also manufacturing ammunition.[12] Remington continues to offer the 6mm BR Remington in the 40-X series rifles.[13] The Remington version of this cartridge is now considered to be obsolete.[12]

### 6mm Norma BR

[edit]

In 1996 Norma of Sweden introduced the 6mm Norma BR which was dimensionally similar to the 6mm BR Remington.[14] However the chamber of the Norma version provided a longer throat making allowances for the seating of very low drag (VLD) bullets.[12] It was designed from the beginning to optimize accuracy, barrel life, and case capacity in a 6 mm cartridge for 300–600 metres (328–656 yd) target shooting. As such it couples a sensible case volume (2.45 ml) to bore area (29.52 mm2/0.2952 cm2) ratio with ample space for loading relatively long slender projectiles that can provide good aerodynamic efficiency and external ballistic performance for the projectile diameter.[14] This is the most common variation of the cartridge used today.[15]

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.[16][17]

## Design

[edit]

The 6mm BR Remington cartridge is a .308×1.5" Barnes cartridge necked down to accommodate .243 bullets. The .308×1.5" Barnes cartridge is based on the .308 Winchester case shortened to 1.5 inches (38 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.[18]

## 6mm Norma BR

[edit]

The 6mm Norma BR cartridge was 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 grains (4.5 g), Norma standardized their set of chambering specifications for a very low drag (VLD) bullet of over 100 grains (6.5 g), thus realizing the long-range capabilities of the cartridge. This required a much longer throat in rifles chambered for the Norma cartridge.[19]

## See also

[edit]

* List of rifle cartridges
* 6 mm caliber

## References

[edit]

1. ^ 6mmBR Cartridge Guide
2. ^ 6 MM B.R. NORMA / 6.8 G (105 GR) SCENAR-L PRODUCT
3. ^ 6 MM B.R. NORMA / 6.8 G (105 GR) SCENAR PRODUCT
4. ^ 6 MM B.R. NORMA / 5.8 G (90 GR) SCENAR-L PRODUCT
5. ^ Simpson, Layne (2005). Layne Simpson's Shooter's Handbook: 600 Questions Answered. Krause Publications. pp. 192–193\. ISBN 978-0-87349-939-2. "The same cartridge in the short action Remington Model 700 rifle and Model Seven carbine would be excellent outfits for varmint shooting"
6. ^ "6mmBR Cartridge Guide". 6mmbr.com. 6mmBR.com. Archived from the original on 24 August 2010. Retrieved 25 September 2010.
7. ^ Whitley, Robert (31 July 2010). "The 6mm BRX — Myth-Busting with Bob Crone". accurateshooter.com. Accurate Shooter. Archived from the original on 2010-08-10. Retrieved 25 September 2010.
8. ^ "6mm Dasher". 6mmhot.com. 6mmhot.com. Retrieved 22 September 2010.
9. ^ "6BR Improved Cartridge Guide". 6mmbr.com. 6mmBR.com. Archived from the original on 15 September 2010. Retrieved 25 September 2010.
10. ^ "Taming a New Wildcat -- 6 UBL Drives 107s to 3005 fps". 6mmbr.com. 6mmBR.com. Archived from the original on 15 September 2010. Retrieved 25 September 2010.
11. ^ Hawks, Chuck (2005). "The 6mm BR Remington". chuckhawks.com. chuckhawks.com. Retrieved 25 September 2010.
12. ^ a b c "6mm Norma BR and 6mm BR Remington". ammo-one.com. Ammo-One. Archived from the original on 27 August 2010. Retrieved 25 September 2010.
13. ^ "40-X Series". remingtoncustom.com. Remington Arms Company Inc. 2010. Archived from the original on 27 September 2010. Retrieved 25 September 2010.
14. ^ a b C.I.P. TDCC datasheet 6mm Norma BR
15. ^ "6mmBR Frequently Asked Questions (FAQ)". 6mmbr.com. 6mmBR.com. Archived from the original on 24 August 2010. Retrieved 25 September 2010.
16. ^ "Lapua Sport Shooting cartridges - the 6mm Norma BR". Archived from the original on 2010-12-04. Retrieved 2010-10-19.
17. ^ 6mm Norma BR DL match cartridge for 300 m rifle shooting product page[permanent dead link‍]
18. ^ De Haas, Frank; Wayne Van Zwoll (2003). "Short Stature, Long Range". Bolt Action Rifles - 4th Edition. Krause Publications. pp. 636–643\. ISBN 978-0-87349-660-5.
19. ^ Barnes, Frank C. (2000). M.L. McPherson (ed.). Cartridges of the World (9th ed.). Iola, Wisconsin: Krause Publications. pp. 2p. ISBN 0-87341-909-X.

## External links

[edit]

* 6mmBR.com - 6mm BR Rifle Shooting and Reloading Information
* 6mm BR Remington page at ChuckHawks.com

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Cartridges derived from the .30-03 Springfield

Prototype|

* .30-01 Thick-Rim

First generation|

| Based on .30-03 Springfield|

* .30-06 Springfield

|

Second generation|

| Based on .30-06 Springfield|

* .250 Savage
* .25-06 Remington
* 6.5-06 A-Square
* .270 Winchester
* .280 Remington
* .30-06 JDJ
* .338-06
* .35 Whelen
* .400 Whelen
* .44 AMP
* .50 BMG
* wildcat cartridges

|

Third generation|

| Based on .250 Savage|

* .22-250 Remington
* 6 mm XC
* .250 Ackley Improved
* .300 Savage

|

Based on .280 Remington|

* .280 Ackley Improved

Based on .50 BMG|

* .416 Barrett
* .460 Steyr
* .510 DTC EUROP
* .55 Boys
* 14.5mm JDJ

Fourth generation|

| Based on .300 Savage|

* .308 Winchester/7.62×51mm NATO

|

Based on .22-250 Remington|

* .22-250 Ackley Improved

Fifth generation|

| Based on .308 Winchester|

* .22 CHeetah
* .243 Winchester
* 6.45×48mm XPL Swiss
* .260 Remington
* 7mm-08 Remington
* .307 Winchester
* .308×1.5-inch Barnes
* 7.62×51mm CETME
* .338 Federal
* .358 Winchester
* .45 Raptor

|

Sixth generation|

| Based on .243 Winchester|

* .243 Ackley Improved

|

Based on .307 Winchester|

* .356 Winchester
* .308 Marlin Express

Based on .308×1.5-inch Barnes|

* .22 BR Remington
* 6mm BR
* .30 BR

Seventh generation|

| Based on 6mm BR|

* 5 mm/35 SMc
* 6mm Dasher
* 7mm BR Remington

|

Based on .22 BR|

* .20 BR

Eighth generation|

| Based on 7mm BR Remington|

* .338 Whisper

|

Related|

* .30 Thompson Center

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Intermediate cartridges

LE & Paramilitary|

* .22 Spitfire
* .221 Remington Fireball
* .300 AAC Blackout
* .375 SOCOM
* .450 Bushmaster
* .45 Raptor
* .458 HAM'R
* .458 SOCOM
* .50 Beowulf
* .500 Auto Max
* 6.5mm Grendel
* 7.62×37mm Musang
* 7.62×45mm Pindad
* 8.6 mm Blackout
* 9×39mm
* .510 Whisper

Service issue|

* 5.45×39mm
* 5.56×45mm NATO
* 5.8×42mm
* .30 Carbine
* 7.62×39mm
* 7.62×45mm
* 7.92×33mm Kurz

Premodern|

* 10.4x38mmR
* 10.4×47mmR
* 11x42mmR Albini-Comblain
* 11×50mmR Comblain
* 11mm Beaumont
* 12.17×42mm RF
* 12x46mmR Musket Spain XPL
* .22 Winchester Centerfire
* .25-20 Winchester
* .32-20 Winchester
* .43 Spanish Carbine
* .45-60 Winchester
* .45-75 WCF
* .433 Egyptian
* .50-70 Government
* 14×33mmR Wänzl
* 15.24х40R Krnka

Commercial|

* Calhoon cartridges
* .20 VarTarg
* 5 mm/35 SMc
* .20 Tactical
* .204 Ruger
* 5.6×39mm
* .22-250 Remington
* .22 PPC
* .219 Zipper
* .224 Valkyrie
* .222 Remington
* .225 Winchester
* 6mm BR
* 6mm PPC
* 6 mm XC
* 6mm ARC
* 6.5mm Creedmoor
* 6mm AR
* 6×45mm
* .25-45 Sharps
* .250-3000 Savage
* 6.5×47mm Lapua
* .277 Wolverine
* 7mm BR Remington
* 7×33mm Sako
* 7.62×40mm Wilson Tactical
* .30 Remington AR
* .350 Legend
* .35 Remington
* .360 Buckhammer
* .400 Legend
* .401 Winchester Self-Loading

Prototype|

* .351 Winchester Self-Loading
* .345 Winchester Self-Loading
* 4.85×49mm
* 5.6x48mm Eiger
* 6×45mm SAW
* 6.45×48mm XPL Swiss
* 6.5×39mm
* 6.8mm Remington SPC
* .280 British
* 7.5×38mm
* 7.5×38mm
* 7.65×33mm
* 7.65×35mm
* 7.75×39mm GeCo
* 7.92×41mm
* 12.7×55mm STs-130

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Remington firearms and cartridges

Rifles|

| Bolt-action|

* .22 Junior Special
* JuniorTarget 521TL
* Remington–Keene rifle
* M1903 Springfield rifle
* Pattern 1914 Enfield
* M1917 Enfield
* Mosin–Nagant
* Model 5
* Model 6
* Model 7
* Model 30
* Model 34
* Model 504
* Model 511
* Model 512
* Model 513
* Model 521
* Model 580
* Model 581
* Model 582
* Model 600
* Model 660
* Model 673
* Model 700
* Model 710
* Model 720
* Model 721
* Model 770
* Model 783
* Model 788
* Model 798
* Model 799
* M24 sniper weapon system
* M2010 Enhanced Sniper Rifle
* Modular Sniper Rifle

|

Pump-action|

* Model Six
* Model 14
* Model 121
* Model 141
* Model 572
* Model 572 Fieldmaster
* Model 760
* Model 7600

Semi-automatic|

* Nylon 66
* Model Four
* Model 8
* Model 24
* Model 241
* Model 522
* Model 552
* Model 597
* Model 740
* Model 742
* Model 7400
* Model 750
* R4
* R5 Remington Gas System
* Model R-25
* RSASS

Automatic|

* Adaptive Combat Rifle

Single shot|

* Rolling block

Shotguns|

| Pump-action|

* Model 10 and 29
* Model 17
* Model 31
* Model 870
* Model 887

|

Semi-automatic|

* Model 11
* Model 11-48
* Model 58
* Model 878
* Model 1100
* Model 11-87
* Model 11-96
* Model SP-10
* SPR 453
* Versa Max
* V3

Break-action|

* SPR 18
* SPR 94
* SPR 100
* SPR 210
* SPR 220
* SPR 310

Handguns|

| Semi-automatic|

* 1911 R1
* Model 51
* R51
* RM380

|

Revolver|

* Remington-Beals
* Model 1858
* Model 1875
* Model 1890

Derringer|

* Model 95
* Rider Single Shot Pistol
* Zig-Zag Derringer

Other|

* Naval Model 1865 Pistol
* XP-100

Cartridges|

* .17 Remington Fireball
* .17 Remington
* 5mm Remington Rimfire Magnum
* .22 Remington Jet
* .221 Remington Fireball
* .222 Remington
* .222 Remington Magnum
* .223 Remington
* .22-250 Remington
* 6mm BR
* 6mm Remington
* .25 Remington
* .257 Roberts
* .25-06 Remington
* .260 Remington
* 6.5mm Remington Magnum
* 7mm BR Remington
* 7mm-08 Remington
* .280 Remington
* 7mm Remington Magnum
* 7mm Remington Short Action Ultra Magnum
* 7mm Remington Ultra Magnum
* .30 Remington
* .30 Remington AR
* .300 Remington Short Action Ultra Magnum
* .300 Remington Ultra Magnum
* 8mm Remington Magnum
* .338 Remington Ultra Magnum
* .35 Remington
* .35 Whelen
* .350 Remington Magnum
* .360 Buckhammer
* .375 Remington Ultra Magnum
* .416 Remington Magnum
* .41 Remington Magnum
* .44 Remington Magnum
* .444 Marlin

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