for those not in the know on this the C7 is a M16 clone in standard issue to Canadian military service.
one of the changes the Canadian design is making is shifting from conventional ammo to cased telescoped ammo. Traditionally used in high powered weapons like tank guns, the US has been working on it for small arms as part of the LSAT program. It offers a 40% weight reduction compared to conventional ammo and is already at technology readiness level 7 after 25,000 rounds were fired in trials in 2011 of the US Lightweight Small Arms Technology LMG of course that's assuming the Canadians are using the exact same rounds.
Remember The US and Canada have a defence relationship that borders on Incest, and by Treaty have to have a high level of commonality of systems.
An additional note of Reality following Art.
note the size of the magazines seen on these, It looks alot bigger then a 30 rounder. makes me wonder if the Canadians are going to make a mock up from the US Army's Objective force Warrior program in particular the Crye Precision MR-C reality?
Although the launcher is below not above the MR-C concept included a 45 or 50 round capacity bullpup in either 5.56mm or 6.8mm. It was never really intended to be more of a stand in for XM8 then the Individual carbine, It did however make a claim to fame in a number of video games and inspired the guns from HALO