.20 BR | ||||||||||||
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Type | Rifle | |||||||||||
Place of origin | USA | |||||||||||
Specifications | ||||||||||||
Parent cartridge | .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 .204" diameter bullet[1] and maintaining the shoulder angle of 30° and case length of 1.535 inches (39.0 mm).[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 40 grain bullet at over 4000fps, 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[]
- ↑ 1.0 1.1 Hamzeh, Kory. "Twenty Caliber Cartridge Guide". http://www.6mmbr.com/20caliber.html. Retrieved 8 July 2013.
- ↑ "Twenty Caliber Cartidge Dimensions". tripledeuce.net. http://tripledeuce.net/Cartridge_Comparisons_0SJN.php. 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.
The original article can be found at .20 BR and the edit history here.