.510 Whisper
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).
.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] |
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 only loses 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 minute of angle, 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 .416 Rigby as the parent case. 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
- 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 Archived 2007-12-10 at the Wayback Machine" by Lukas Kruesi, New Zealand Guns & Hunting, September/October 2003