So to look at the potential for the new Russian small arms family, lets look at the various weapon types that could be incorporated... based on existing types.
At the small end we have the Vityaz and Bizon SMGs which are loosely based on the AKS-74U and are chambered in 9x18mm and 9x19mm pistol calibres.
Next up we have the SMG in assault rifle calibre, or the AKS-74U itself.
Then comes the short barrel carbine in the form of the AK-105.
Next is the AK-74M which is the 5.45mm full length rifle in the AK-100 series.
Then you would also have the AK-9 in 9 x 39mm calibre as a specialist weapon.
Above that would be a weapon along the lines of the DT or ASh-12 in 12.7 x 55mm calibre.
The next weapon up would be the RPK-74.
Then an RPK-74 length weapon in a more powerful calibre in the class of the SVD.
At the top of the scale we would have the PKM/PKP class weapon in a heavy calibre and belt fed.
So this means a pistol calibre SMG, an assault rifle calibre SMG, a short barrel carbine, an assault rifle, a specialist silenced assault rifle, a specialist silenced sniper rifle, a LMG, a desingated marksman rifle, and a GPMG.
If I was designing them the pistol calibre would be 9 x 21mm, the assault rifle would be 5.45 x 39mm, the silenced assault rifle would be in 9 x 39mm and the silenced sniper rifle would be in 12.7 x 55mm and the LMG, the DMR, and the GPMG would all be in 6 x 49mm.
The LMG and GPMG will be belt fed and the DMR would have 25 round magazines, while the assault rifles will have 60 round mags in 5.45mm calibre and 30 rounds in 9 x 39mm and 20 rounds in 12.7 x 55mm. The 9 x21mm mags will be 20 and 40 round capacity sticks or 64 round spiral tube mags.
Like the AK-12 the new guns will be modular, with box feeds for everything except LMG and GPMG.
The LMG, heavy suppressed sniper rifle, DMR, and GPMG will be larger heavier weapons with stronger frames, the assualt rifle calibre weapons will be medium framed weapons and the pistol calibre SMGs will be light framed weapons.
The assault rifles would be bullpups to reduce length.