Copyright International Ammunition Association, 2005. All rights
reserved.
Cartridge of the Month
October 2005
9 x 51mm SMAW (Shoulder Launched Multipurpose Assault
Weapon) Specimen and photos courtesy of Paul
Smith
This is the training/spotting cartridge used with the 83 mm SMAW
rocket launcher deployed by the U. S. Marine Corps beginning in 1984. The
rocket launcher is based on the Israeli B-300 system. A British designed 9mm
spotting rifle is mounted on the right side of the launcher.
The rocket launcher is reusable and each rocket comes in a disposable sealed
tube which is affixed to the launcher. There are different 83mm high explosive
rockets which include anti-armor (HEAA) and a dual purpose anti-fortification
(HEDP) rounds.
The 9mm rifle is used for for spotting to increase the first round hit probability
with the rocket round, and for use in training. The British origin of the
spotting rifle accounts for the British headstamp (RG for Radway Green) on
the round shown below. The round illustrated is only a tracer loading. A spotter-tracer
loading is also made.
The round consists of a necked-up 7.62 x 51 case fitted with a lead projectile,
gilding metal cap and a trace cannister at the rear. The parent case has been
modified to accept a .22 Hornet case which holds the powder charge and is
crimped and sealed..
The only headstamp which is legible is the one on the .22 Hornet case which
is: RG 83.
Paul added the following information and photos, thanks to an anonymous source:
"The Shoulder-fired Multipurpose Assault Weapon (SMAW) system
was managed by the Navy lab at Dahlgren, VA (NSWC Dahlgren Div) for the Marine
Corps at Quantico, VA. The cartridge was therefore assigned nomenclature in
accordance with Navy practices and bears the official designation of Mark 217
Mod 0.
Quite interesting about this cartridge is the fact that the 9mm
spotting rifle operates semi automatically by means of primer actuation. In
this concept the primer sets back rearward upon firing to unlock the breech
bolt. Fired 9mm spotting cases look rather peculiar because the 22 Hornet case
backs out about 1/4 inch. This idea of primer actuation was conceived by John
Garand (who was a notable Canadian by birth). Garand experimented with several
prototype semi automatic rifles using primer actuation in the early 1920s while
at Springfield Armory. Some specially primed cartridges were loaded by Frankford
Arsenal for Garand's experiments but he abandoned the idea in 1926 when he learned
that the Ordnance Corps had decided to secure primers in the case as a general
practice by means of mechanical crimping, such primer crimping being required
by machine guns.
Engineering for the SMAW and its 9mm spotting rifle was performed
by Royal Ordnance people in UK. They deserve a word of recognition for having
successfully fielded a primer actuated small arms weapon in US military service.
John Garand would be proud to know that his idea had sufficient merit to eventually
be fielded.
Here are photos of the MK 217 cartridge carton and a photo of
the fired case showing the primer set back about 1/4 inch, enough to unlock
the spotting rifle's breech."
