6mm BR

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.

6mm BR Remington
6mm BR, 6mm Dasher and .308 Winchester cartridges
TypeRifle
Place of originUnited States
Production history
DesignerWildcats: Various
Commercial: Mike Walker
DesignedWildcats: 1962-1963
Commercial: 1978
Produced1978-present
VariantsSeveral. See article.
Specifications
Parent case.308 Winchester
Case typeRimless, 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 length1.560 in (39.6 mm)
Primer typesmall rifle
Maximum CUP52,000 CUP
6mm Norma BR
TypeRifle
Place of originSweden
Production history
ManufacturerNorma
Produced1996
Specifications
Parent case6mm BR Remington
Case typeSemi-rimmed, Bottleneck
Bullet diameter0.243 in (6.2 mm)
Land diameter0.236 in (6.0 mm)
Neck diameter0.271 in (6.9 mm)
Shoulder diameter0.458 in (11.6 mm)
Base diameter0.469 in (11.9 mm)
Rim diameter0.473 in (12.0 mm)
Rim thickness0.054 in (1.4 mm)
Case length1.560 in (39.6 mm)
Overall length2.440 in (62.0 mm)
Case capacity38-39.5 gr (2.45-2.55 ml)
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):
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.