First time I’ve been able to see the very well known Polish MSBS rifle system in the flesh. In terms of function it’s nothing that’s revolutionary, however a lot of investment has gone in to producing the modular components of this rifle. The quick change barrels can be swapped between CQB carbine length, infantry rifle, DMR and LMG. With the upper receiver being the common component each of those configurations is available in both bullpup and conventional layouts. There’s also a compatible 40mm launcher available.
Great 3D viewer with more information here: