Earlier this month, the Serbian Army debuted a new 6.5 Grendel weapon system, developed by Zastava. The rifle, called M17, is a heavily modified variant of the M70 AK family that has been developed by the company for decades. It incorporates a number of significant new features and improvements detailed below. The new rifle comes as part of an infantry upgrade for the Serbian Army which includes new 7.62x54R rifles, optics, helmets, and load-bearing equipment. This development marks the first adoption of the 6.5 Grendel round as standard by a national military force. The new rifle is advertised to be half a kilogram lighter than the previous rifle, although it’s not clear whether that is supposed to be the 7.62x39mm M70 or the 5.56x45mm M21. Reportedly, the rifles and the new caliber have not yet been adopted, but are still in testing.
In the photo below, you can see a short-barreled version of the M17 (evidently also in 6.5 Grendel) from the left side, showing the ambidextrous safety lever:
The new weapon also features an AR-15 style t-shaped charging handle, integrated monolithic dust cover/gas tube cover with a full length picatinny rail, folding/collapsing ACR-style stocks, and a quick-change barrel mechanism that also appears to be free-floating. This can be seen in the video embedded below starting at about 1:45:
At 2:03 in the video, you can see the special loads intended for the M17, both of which are apparently armor piercing. The first load has a 1.23 gram hardened steel core in a 93gr (6 g) bullet, fired at 2,890 ft/s (880 m/s). The second has a 1.5 gram tungsten carbide core in a 113 grain (7.3 g) bullet, fired at 2,620 ft/s (800 m/s). These velocities are probably taken from the barrel of the M17 DMR variant, which appears to be approximately 20″ long.
The lighter projectile fired at a higher muzzle velocity makes considerably more sense to me versus the traditional heavy projectile medium velocity configuration that the Grendel is famous for. A higher muzzle velocity reduces the drop of the round and extends its effective range, and while a lighter projectile does sacrifice retained energy at extended ranges, the high velocity configuration balances the factors of target effect and hit probability much better, in my opinion.