Russia is not likely to change.
I highly doubt that the russiand are likely to change to the 6.5 Grendel, even ig all they have to do is rebarrel, change the bolt head, and use different magazines.
The reasoning is purely economic. In a time when every country including russia is broke, to change calibers of weapons is an unnneccisary thing. The 5.45mm in their ak-74's suffers from the same issues as the 5.56 of the m16, but that doesnt mean that it doesnt work.
What russia has to its advantage here is that the Ak-47's in 7.62x39 is plenty effective and is accurate enough within regular combat distances. Hell, I've seen some Ak-47's that could hold 2 MOA. These weapons are still so abondant in Russia that front line units can most likely use them if the Ak-74's aren't up to par.
It's like every time the us military is rumered to be changing calibers or even weapons soon. Special forces get to play with the new toys, but no body else ever sees them. Its simply econmically unfeasable. Although, if anyone in charge of our military's weapon aquierment is reading this, change caliber, not weapon. I'll buy a new barrel and bolt head in a day, I dont have the money to buy a weapon thats worth 2g's for civilians!
