.243 WSSM

Infobox Firearm Cartridge
name= 243 WSSM


caption=
origin= USA
type= Rifle
service=
used_by=
wars=
designer= Browning / Winchester
design_date=2003
manufacturer=Winchester
production_date=
number=
variants=
is_SI_specs=
parent=.300 WSM
case type=Rimless, bottleneck
bullet=.243
neck=.291
shoulder=.544
base=.555
rim_dia=.535
rim_thick=.054
case_length=1.670
length=2.36
rifling=1-10"
primer=Large rifle
is_SI_ballistics=
bw1=58
btype1=VMax
vel1=4068
en1=2132
bw2=70
btype2=BT
vel2=3707
en2=2136
bw3=80
btype3=BTSP
vel3=3545
en3=2233
bw4=90
btype4=SFT
vel4=3280
en4=2151
bw5=100
btype5=BTSP
vel5=3136
en5=2184
test_barrel_length=24"
balsrc= Hodgdon [http://data.hodgdon.com/cartridge_load.asp .243 WSSM data data at Hodgdon Online] ] The 243 Winchester Super Short Magnum or 243 WSSM is a fairly new rifle cartridge, introduced in 2003. It uses a shortened .300 WSM (Winchester Short Magnum) case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of efficiency. [ [http://www.browning.com/products/features/detail.asp?ID=2 Browning WSSM info] ] The correct name for the cartridge, as listed by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI), is 243 WSSM, without a decimal point. [ [http://www.saami.org/ Sporting Arms and Ammunition Manufacturers' Institute] ]

Design

The 243 WSSM is an addition to the Winchester Super Short Magnum (WSSM) family of cartridges, which also include the .223 WSSM and the .25 WSSM, and the idea behind the 243 WSSM was to develop a compact, higher velocity version of the well-established and internationally popular .243 Winchester unveiled by Winchester in 1955.

The 243 WSSM's case is unusually short and fat in profile, contrasting markedly with most other rifle cartridges, and is intended to take advantage of what ballisticians have shown is the more uniform and efficient burning of propellant powder when it is held in a short, fat stack by the cartridge case.fact|date=August 2007

Problems

Short fat cases with an abruptly angled shoulder have a history of being difficult to feed properly from the magazines of some rifles. [ [http://www.benchrest.com/forums/showthread.php?t=17770 Benchrest.com Forums] ] In addition, during its short life the WSSM family of cartridges has already gained a reputation for being hard on gun barrels because of the high velocities involved, although this is a point of some dispute among various knowledgeable gun owners and expert writers.

Some rifle manufacturers such Browning have also taken to chrome-lining their barrels' bores to make them less susceptible to the wear caused by the high levels of bullet friction and very high propellant gas temperatures that occur with WSSM cartridges.

Performance

In their ballistics tables, Winchester list a very high muzzle velocity of convert|4060|ft/s|m/s|abbr=on with a convert|55|gr|g|sing=on projectile for this cartridge. [ [http://www.winchester.com/products/catalog/cfrdetail.aspx?symbol=SBST243SS&cart=MjQzIFdTU00= Winchester .243 WSSM Ammunition] ] Based on Hodgdon reloading data typical velocities should range from approximately convert|4000|ft/s|m/s|abbr=on with a convert|58|gr|g|sing=on bullet to approximately convert|3000|ft/s|m/s|abbr=on with a convert|100|gr|g|sing=on bullet. The percentage gain in performance over the older .243 Winchester is around 10% or less, and it remains to be seen if the market will offer a commercially viable place to two 6 mm sporting cartridges that have such similar performance.

This cartridge is usually used for small game such as varminting, and used for animals as big as deer.

ee also

* List of rifle cartridges

References

* [http://www.stevespages.com/jpg/cd243wssm.jpgCartridge Dimensions] at Steves Pages

External links

* [http://www.243wssmhunter.com/ Disabled hunter hunts with a 243 WSSM]
* [http://www.snipercountry.com/Articles/243_WSSM.asp 243 WSSM – The Long-Awaited 6 mm "Answer"?] By Bill Prudden
* [http://www.chuckhawks.com/243wssm.htm The 243 WSSM] by Chuck Hawks
* [http://www.browning.com/products/features/detail.asp?id=73 The Experts Agree - The WSSMs are Winners!] Browning
* [http://www.gunsandammomag.com/reloads/gar0504/ The 243 WSSM] at Guns & Ammo