.20 BR
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.20 BR | ||||||||||||
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Type | Rifle | |||||||||||
Place of origin | USA | |||||||||||
Specifications | ||||||||||||
Parent case | .22 BR | |||||||||||
Bullet diameter | .204 in (5.2 mm) | |||||||||||
Neck diameter | .232 in (5.9 mm) | |||||||||||
Shoulder diameter | .459 in (11.7 mm) | |||||||||||
Base diameter | .470 in (11.9 mm) | |||||||||||
Rim diameter | .473 in (12.0 mm) | |||||||||||
Rim thickness | .054 in (1.4 mm) | |||||||||||
Case length | 1.535 in (39.0 mm) | |||||||||||
Primer type | small rifle | |||||||||||
Ballistic performance | ||||||||||||
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Source(s): 6mmbr.com |
The .20 BR is a centerfire wildcat rifle cartridge. It is based on the .22 BR Remington case necked down to accept a 5.2 millimetres (0.204 in) diameter bullet[1] and maintaining the shoulder angle of 30° and case length of 39 millimetres (1.535 in).[2] The cartridge features a short fat case which is reputed to be both efficient and accurate.[3]
The large powder capacity of the case allows it to propel a 2.6 grams (40 gr) bullet at over 1,200 metres per second (4,000 ft/s), however the cartridge is considered overbore and can be expected to have a relatively short barrel life.[1]
The inherent accuracy of the BR case design and the high performance of the .20 BR has led to it being adopted by varmint hunters and target shooters.[citation needed]
Advantages of this cartridge include; its ability to be chambered in any rifle action which has the .308 Winchester sized bolt face; its short length enables action makers to utilise shorter ports to increase rigidity; and cases are easily formed and loaded.[citation needed]
See also[]
References[]
- ^ a b Hamzeh, Kory. "Twenty Caliber Cartridge Guide". Retrieved 8 July 2013.
- ^ "Twenty Caliber Cartridge Dimensions". tripledeuce.net. Retrieved 8 July 2013.
- ^ De Haas, Frank; van Zwoll, Wayne (2003). "Short Stature, Long Range". Bolt Action Rifles - 4th Edition. Krause Publications. pp. 636–643. ISBN 978-0-87349-660-5.
- Pistol and rifle cartridges
- Wildcat cartridges
- Ammunition stubs