Having one in 5.56mm NATO seemed like a good thing.
I already have a "rock and roller" in 7.62x39mm.
The 7.62 krink "was" (when I got it ) a 5.56mm form four fixed stock Polytech machinegun...Didn't have to change the front trunnion or disturb the serial number to "do" the caliber change. Just took some very careful cutting and the welding up of some "old" rear trunion rivet holes. I will soon add a Russian OMP and re-finish it with Gun Kote.
I am now building the "leftover" Polytech 5.56mm "parts" into a 5.56mm, underfolding stock, underfolding "spike bayonet" semi auto, title 1 rifle which will accept standard bulgarian 5.56mm, polymer "waffle mags." Instead of them damn hi-priced polytech 5.56mm mags.