How? Beretta MX4 (9x19mm) is the size of an AR 15 pistol (5.56x45mm). You can get a JVPC carbine (5.56x30mm) for much less!
Comparison :
AR 15 (5.56x45mm)
JVPC (5.56x30mm)
MX4 STORM (9x19mm)
Although
@Kunal Biswas already replied, I would just highlight the aspect.
I was talking about increase in operational cost of the troops. ITBP or BSF operates three different caliber as of now.
5.56 NATO
7.62 AK
9x19 parabellum.
These are standard operating rounds available at any given time apart from few special ones. Now bring in 5.56 MINSAS and it mean 4 different rounds. Operational cost for any commander would increase with that.
We can't replace any of the existing rounds with MINSAS as of now.
Another aspect for non deployment of JVPC on front line is its maturity. As a weapon system it has not matured enough. It would be good to deploy them with CISF as replacement for 9 mm SMG forst and let it mature enough.