Batob do you have performance specifications for the 6.5x39/6.5 Grendel? What weight bullet? 110 grains? 123 grains? What muzzle velocity per barrel length?
Man it is too early and it is very hard to find numerous informations. Everyting I hear I will write here and explain more if u have questions, it is not secret. So I understand what you ask. On serbian forums they speak the same. We heard there will be 3 types of military 6.5x39 at least and one of them for sniper (dmr M17) but what will be difference between that round and standard round we have no idea. On testings off course they know velocity weight and so on but they still dont speak about it. We should be thankfull that there is internet and at least we can share very interesting informations of making a new rifle. But personaly I understand why some people (from Zastava) stoped talking abut this rifle. For ex. in some testings for riability they tested 2 barrels each shot 13 000 rounds with same rifle, case just changing barrels and shoting not one problem. It was with standard serbian military 7.62x39. Than when PPU was developing their military 6.5x39 Zastava sent them rifle for testing. Everyting was ok but from PPU they said they had malfunctions.
So somebody can say it is not reliable rifle but in Zastava it was probably like this = "put that nice new barel on worst junk that was very much abused they will have problems but who cares no big deal barel is new."
Also, problem with information about this rifle is conected with politics. Serbian military general Dikovic said at the end of 2018 ALL serbian army will get new M17 to replace M70. Politicians say the same but not only rifles but new uniforms equipments and so on. So when they presented M17 to politicians 7-8 days ago it was with other equipment and uniforms also so they were not specific in details just about rifle. Going back to your question, here on this link
Dynamic Demonstration of a Part of the Project ?1500+? | Ministry of defence Republic of Serbia
In last video u can see from 1:30 sec soldier changing barels but old guy in uniform behind him is probably not soldier in my opinion.
edit: here is youtube link to the video