.510 Whisper
.510 Whisper | ||||||||
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Type | Rifle | |||||||
Place of origin | USA | |||||||
Production history | ||||||||
Designer | SSK Industries | |||||||
Specifications | ||||||||
Parent case | .338 Lapua Magnum | |||||||
Case type | Rimless, bottleneck | |||||||
Bullet diameter | .510 in (13.0 mm) | |||||||
Neck diameter | .549 in (13.9 mm) | |||||||
Shoulder diameter | .587 in (14.9 mm) | |||||||
Base diameter | .587 in (14.9 mm) | |||||||
Rim diameter | .588 in (14.9 mm) | |||||||
Case length | 1.875 in (47.6 mm) | |||||||
Overall length | 3.34 in (85 mm) | |||||||
Ballistic performance | ||||||||
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Source(s): SSK Industries [1] |
The .510 Whisper is a subsonic rifle cartridge developed by SSK Industries for use in suppressed rifles.[2] It fires a .51-caliber bullet weighing 750 gr (49 g) at roughly 1,050 ft/s (320 m/s).
Overview
Despite the large bullet, this round is very quiet, similar to the noise from a .22 Short when used with a suppressor. When used with a very high ballistic coefficient bullet, the round has only lost about 100 ft/s (30 m/s) out to over 500 yards. This gives it more downrange energy at that distance than traditional .30 caliber rounds such as the .308 Winchester and .300 Winchester Magnum.[3] SAKO TRG-S test rifles have achieved MOA and better accuracy with this cartridge at 600 yards.[2]
Powders such as H110, 4227, or surplus WC820 are well suited for subsonic loads and give a low standard deviation. Necessary components such as barrels, reloading dies, etc. are available from SSK. Sako TRG-S actions are most often converted to this caliber. The Thompson Center Encore is also suitable, but is rather lightweight for shooting this heavy recoiling cartridge, especially when using 950-grain (62 g) bullets.
Design
The case of the .510 Whisper is based on the .338 Lapua Magnum that has been trimmed down to a length of 1.875 in (47.6 mm) and necked-up to accept a .510 in (13.0 mm) diameter bullet. Neck wall thickness is reduced to 0.013 in (0.33 mm) and a small shoulder is cut into the body for headspacing. Overall length of the loaded round is about 3.34 in (85 mm).
See also
- 12 mm caliber
- Glossary of firearms terminology
- List of rifle cartridges
- Whisper Family of Firearm Cartridges
References
- ↑ SSK Industries homepage
- 1 2 Barnes, Frank C. (2006) [1965]. Skinner, Stan, ed. Cartridges of the World (11th ed.). Iola, WI: Gun Digest Books. p. 282. ISBN 0-89689-297-2.
- ↑ "Whisper cartridges" by Lukas Kruesi, New Zealand Guns & Hunting, September/October 2003