An image posted to Twitter on October 20, 2015, appears to show a Jabhat al-Nusra fighter in Syria wielding a United States-made M240 series general-purpose machine gun (GPMG), purportedly taken from the US-equipped Free Syrian Army’s Division 30. It is likely to be either an upgraded M240B or an M240L. The M240L was only type-classified in 2010, which would make its presence in the hands of Jabhat al-Nusra fighters particularly significant.
Chambered for 7.62 x 51 mm, the M240L represents the most modern iternation of the M240 series, making use of titanium in its construction and featuring a lightweight (5.8 lbs) barrel to reduce its overall weight by almost 2.5 kg compared with the M240B. The M240L is one of the weapon systems believed to have been issued to Division 30. Previous social media posts show members of Division 30 armed with M240L GPMGs.
Other US materiel is known to have been transferred from Division 30 to Jabhat al-Nusra, with US CENTCOM confirming in late September 2015 that some of the US-trained and equipped fighters had surrendered vehicles and ammunition. In early October 2015, US officials stated that they were abandoning the remainder of the program to train and equip moderate Syrian rebels and would instead increase support to other established forces in the region, predominantly Kurdish forces.
New model bipods and collapsible butt stocks have also been fitted to legacy M240B GPMGs. The weapon pictured could be an M240B, with these upgrades, but from imagery available this is difficult to confirm. WhilE sources have claimed M240L GPGMs were issued to Division 30 fighters, it is unclear if upgraded M240B models were also issued.
M240L Technical Specifications
Calibre: 7.62 x 51 mm NATO
Barrel length: 21.7?
Overall length: 48.5?
Overall weight: 22.3 lbs. (with standard barrel and fixed stock)
Rate of fire: 550 to 650 rounds per minute
Technical specifications taken from FN Herstal USA. With thanks to @AbraxasSpa.