.338 Whisper

Infobox Firearm Cartridge
name= .338 Whisper


caption=
origin= USA
type= Rifle, subsonic
service=
used_by=
wars=
designer= J.D. Jones
design_date=1990s
manufacturer=SSK Industries
production_date=
number=
variants=
is_SI_specs=
parent=7 mm BR or .221 Fireball
case_type=Rimless, bottleneck
bullet=.338
neck=.360
shoulder=.457
base=.463
rim_dia=.466
rim_thick=.048
case_length=1.47
length=
rifling=
primer=
is_SI_ballistics=
bw1=200
btype1=BT
vel1=1077
en1=515
bw2=250
btype2=BT
vel2=1040
en2=600
bw3=300
btype3=BT
vel3=1050
en3=735
bw4=
btype4=
vel4=
en4=
bw5=
btype5=
vel5=
en5=
test_barrel_length= 12"
balsrc= Cartridges of the World * cite book
last = Barnes
first = Frank C.
editor = Skinner, Stan
title = Cartridges of the World
edition = 11th Edition
origyear = 1965
year = 2006
publisher = Gun Digest Books
location = Iola, WI, USA
pages = 252, 284
isbn = 0-89689-297-2] The .338 Whisper is a wildcat cartridgein the Whisper family, a group of cartridges developed in the early 1990s by J.D. Jones of SSK Industries. Unlike the smaller caliber cartridges in the Whisper family, loads for the .338 Whisper are mainly limited to subsonic velocities. [http://www.lasc.us/RangingShot338WhisperRevisited.htm User "Review" on the .338 ammo]

Versions

There are two versions of the .338 Whisper:

#The original .338 Whisper is based on the 7 mm Remington Bench Rest case, necked up (enlarged) to take a .338" bullet. As the 7mm Bench Rest and .308 Winchester cases share the same case head dimensions, conversion to .338 Whisper from a rifle previously chambered in .308 Winchester (or any cartridge based on the .308 Winchester case, such as .243 Winchester, .260 Remington, 7 mm-08 Remington, etc...) is a relatively simple task. http://www.reloadersnest.com/frontpage.asp?CaliberID=389 Information on the two different whisper versions]
#The second version (called .338 Whisper #2 by SSK) is based on the .221 Remington Fireball case, simplifying conversion of firearms chambered in 5.56x45mm or its commercial counterpart, .223 Remington.

ubsonic

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 which contributes in large part to the overall noise produced when using a firearm. Subsonic loads are often designed to avoid the turbulent transonic zone entirely. This allows the cartridge to be sound suppressed relatively easily. To ensure terminal performance at subsonic velocities, heavy bullets for the caliber (250-300 grains) (16.20-19.44g) are desirable.

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" or ".300-221".

See also

* List of rifle cartridges
* 8 mm caliber

References

External links

* [http://www.sskindustries.com/ SSK Industries]