Quote Originally Posted by BoringGuy45 View Post
What about the 55x design makes it so that the upper has to be steel instead of machined aluminum? Hypothetically speaking, if someone wanted to make a next gen rifle based on the 55x design, would it be possible to make it entirely aluminum (for weight saving, as that seems to be all the rage these days)?

My main reason for asking is pure curiosity, as I've always be interested in the SG55x series, and I'm just trying to learn a bit more about their engineering.
Of course it’s possible. But costly. Not likely to see this unless the Swiss military specs as such for their next rifle.