Page 130 - Australian Defence Magazine Sep-Oct 2022

130 LAND WARFARE
SMALL ARMS
SEPTEMBER-OCTOBER 2022 | WWW.AUSTRALIANDEFENCE.COM.AU
LEFT: A US soldier equipped with M5 rifle during the NGSW trials program
program to come up with suitable cartridges and weapons to fire them.
That came down to a shortlist of three – SIG Sauer US, General Dynamics and Textron Systems – each proposing its own cartridge design and weapons.
Over a 27-month weapon trials period, more than 1,000 US soldiers, Marines and special forces tried out the new weapons.
In April this year, the US military announced the winner – SIG Sauer with its M5 rifle, a de- rivative of its MCX, and M250 belt- fed LMG, both chambered for their
13,000 M250 LMGs under a US$4.7 billion contract with SIG Sauer.
The US military has awarded Olin Winchester, which operates the Lake City Ammunition Plant, a US$15 mil- lion contract to design a new plant for NGSW ammunition. Until then, SIG Sauer will supply the cartridges.
It is possible that the US will adopt two natures of am- munition – conventional brass-cased cartridges with lower pressure and reduced performance for training and the steel-based full power rounds for service.
The extended phase-in of the new weapons means exist- ing weapons and their ammunition will be around for years. So, what’s so special about these new guns and their am-
munition?
The new cartridge is certainly heavier than 5.56 but ap-
parently a bit lighter than 7.62. An unloaded M5 is two pounds heavier than an unloaded M4, The M250 is four pounds lighter than the M249.
Putting that in perspective, the M5 weighs in about the same as the legacy Australian SLR.
DESIGN INNOVATION
The new weapons feature a number of innovations. Both feature a combined suppressor and flash hider to manage what would otherwise be ferocious muzzle blast.
M5 is gas-operated with a short stroke piston and rotat- ing bolt with 16-inch barrel, readily exchangeable to cali- bres such as 7.62 NATO or 6.5 Creedmoor.
The M5 features controls similar to the M4 but ambi- dextrous. It retains the AR pattern ambidextrous cocking handle, with the addition of a non-reciprocating cocking handle on left side, just like the SLR.
Both are interesting new weapons with a new cartridge, but technologically not a great advance on what came before. Perhaps the greatest innovation is in their optics. The
“FOR SELF-SUFFICIENCY AND NATIONAL SOVEREIGNTY, AUSTRALIA WOULD WANT TO MANUFACTURE WEAPONS AND THEIR AMMUNITION LOCALLY”
new 6.8x51 cartridge.
This cartridge looks much like the
familiar 7.62 NATO (or in civilian terms .308 Winchester). The big dif- ference is a stainless-steel base with aluminium locking washer attached to a conventional brass body.
That allows much higher operat- ing pressures than a traditional brass case – 80,000 psi as against 62,000 psi for the 7.62 – driving the projec-
tiles at 3000 fps, with improved performance at long range and against body armour.
The US Army has revealed few details of the cartridge’s actual ballistics, other than assurances that it delivers greater energy at close and long ranges than do current systems.
It was planned that the first of the new weapons would be in the hands of US soldiers by October next year.
That may be delayed after one losing bidder lodged a formal complaint. The company subsequently withdrew its complaints, allowing production to proceed.
In all, the US Army plans to buy 107,000 M5 rifles and
SIG SAUER US