Whisper (cartridge family)

The Whisper family of firearm cartridges is a group of wildcat cartridges developed in the early 1990s by J.D. Jones of SSK Industries. The Whisper Family was developed as a line of accurate, multi-purpose cartridges using relatively heavy rifle bullets for a given caliber in subsonic loads. The intention was to create an extremely accurate cartridge family for military, police, competition and specialized hunting markets that could also be easily sound suppressed.

While all cartridges in the Whisper family must be capable of accuracy using subsonic loads, most of the smaller caliber cartridges of the family (.308" and under) are also capable of being loaded to supersonic velocities using relatively lightweight bullets for their caliber, increasing their utility.

Subsonic cartridges

A subsonic cartridge is designed to fire its bullets at velocities slower than the speed of sound (1128 ft/s at 70 °F) to avoid the sonic crack caused by the bullet breaking the sound barrier. This allows the cartridge to be sound suppressed relatively easily. Additionally, in some cases, subsonic loads are often intended to avoid the turbulent transonic zone entirely, maximizing potential accuracy.

Whisper cartridge cases

The Whisper Family
Cartridge Parent Case
6mm Whisper .221 Fireball
6.5mm Whisper .221 Fireball
7mm Whisper .221 Fireball
.300 Whisper .221 Fireball
.338 Whisper #2 .221 Fireball
.302 Whisper 7mm BR
.338 Whisper 7mm BR
.375 Whisper 7mm BR
.416 Whisper 7mm BR
.458 Whisper .458 Winchester Magnum
.500 Whisper .460 Weatherby Magnum
.510 Whisper .338 Lapua Mag

Yet another consideration of the Whisper Family design is that all of the cartridges are based on existing cases that utilize common case head dimensions. This allows rifles with common bolt face dimensions to be converted to a Whisper cartridge fairly easily, often requiring only the rifle's action to be re-barreled. There are four "series" within the Whisper Family, each using a different parent case.

Mini and Micro Whispers

There are also two little-known cartridges of the Whisper Family based on handgun cartridge cases. These are the 7.62 Micro Whisper, based on the .30 Luger case; and the 7.63 Mini-Whisper, based on the .30 Mauser case. Like the rest of the Whisper Family, these two cartridges are designed to fire rifle bullets at subsonic velocities.

Trademark

"Whisper" is a registered trademark of SSK Industries. In order to sidestep this branding (and/or any licensing fees required to use the "Whisper" name legally), other manufacturers tend to use different names for cartridges in the Whisper family. For example, the .300 Whisper (the most popular cartridge of the family) is often called ".300 Fireball", .300 Blackout, or ".300-221".

External links

This article is issued from Wikipedia - version of the 7/22/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.