The .500 Whisper or .500 Whisper Short Belted 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 .500 Whisper (metric: 13x57mm B
by Anthony G Williams, ''CARTRIDGES FOR SILENCED SNIPING RIFLES'', January 2013) is the first of two 1/2 inch caliber rounds developed by J. D. Jones with a specific focus on the Thumper concept and subsonic use. Being based on the .378 Weatherby Magnum case, it is a belted and bottlenecked cartridge. Later, J. D. Jones went on to develop the similar .510 Whisper round. This has a roughly 0.4 inch (10 mm) shorter non-belted bottlenecked case based on the .416 Rigby. Despite the large bullet, this round is very quiet when using a

suppressor A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that reduces the acoustic intensity of the muzzle report (sound of a gunshot) and muzzle rise when a gun (firearm or air gun) is discharged, b ...

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 The .308 Winchester is a smokeless powder rimless bottlenecked rifle cartridge widely used for hunting, target shooting, police, military, and personal protection applications globally. It is similar but not identical to the 7.62×51mm NATO ...

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, whi ...

. Necessary components such as barrels, reloading dies, etc. are available from SSK.

Sako Sako or SAKO may refer to: People with the surname * Bakary Sako (born 1988), French-born Malian footballer * Hygerta Sako, Albanian beauty pageant contestant * Louis Raphaël I Sako (born 1948), Iraqi cleric, head of the Chaldean Catholic Churc ...

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 .500 Whisper is derived from the big-bore belted family of cases developed by

Roy Weatherby Roy Edward Weatherby (4 September 1910 — 4 April 1988), was the founder and owner of Weatherby, Inc., an American rifle, shotgun and cartridge manufacturing company founded 1945. Weatherby created an entire line of custom cartridges, and was ...

in the 1950s ( .378 Weatherby Magnum, .460 Weatherby Magnum). It can also be viewed as a shortened version of another .510 caliber cartridge based on the .378 Weatherby Magnum, the .500 A-Square (13x73 mm B) developed by

Arthur Alphin Lieutenant Colonel Arthur ("Art") B. (Brent) Alphin (born September 5, 1948) is a retired United States Army officer and military historian. He is the founder and owner of A-Square, manufacturer of American hunting rifles. He taught military h ...

in 1976. The overall length of the loaded round is about which is identical to the .300 Winchester Magnum round to be able to fit magazines and actions of other common

belted magnum The term belted magnum or belted case refers to any cartridge, but generally a rifle cartridge, with a shell casing that has a pronounced "belt" around its base that continues 2–4 mm past the extractor groove. This design originated with the B ...

rifles.

References

{{DEFAULTSORT:500 Whisper Pistol and rifle cartridges Whisper cartridges Subsonic rifle cartridges

Overview

Design

See also

References