The .510 Whisper is a
subsonic rifle
cartridge developed by
SSK Industries for use in suppressed rifles.
It is capable of firing a .51-caliber bullet weighing at roughly .
Overview
The .510 Whisper (13×47 mm) is the second of two 1/2 inch caliber rounds developed by
J. D. Jones with a specific focus on the
Thumper concept and
subsonic use. Based on the
.416 Rigby case, it is a
non-belted and
bottlenecked cartridge.
Earlier
J. D. Jones had already developed the similar
.500 Whisper round, which has a roughly 0.4 inch (10 mm) longer belted bottlenecked case based on the
.378 Weatherby Magnum.
Despite the large bullet, this round is very quiet when using a
suppressor due to the subsonic nature of the cartridge. When used with a very high ballistic coefficient bullet, the round only loses about 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.
[Whisper cartridges]
" by Lukas Kruesi, ''New Zealand Guns & Hunting'', September/October 2003 Sako
TRG-S test rifles have achieved
minute of angle
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The n ...
, and better, accuracy with this cartridge at 600 yards.
Powders such as H110, 4227, or surplus WC820 are well suited for subsonic loads and give a low
standard deviation
In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, whil ...
. 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 bullets.
Design
The case of the .510 Whisper is based on the
.416 Rigby (same as the
.338 Lapua Magnum) as the parent case. Overall length of the loaded round is about .
See also
*
Whisper Family of Firearm Cartridges
*
12.7×55mm STs-130
*
12 mm caliber
*
Glossary of firearms terminology
*
List of rifle cartridges
References
{{DEFAULTSORT:510 Whisper
Pistol and rifle cartridges
Whisper cartridges
Subsonic rifle cartridges