This is a great write-up about the new rifles competing for the Army contract. My son is the Editor in Chief for Task & Purpose and he has a great bunch of writers that put out fantastic articles every day. There's a video in this article that gives an inside look at Sig's testing and manufacturing that really impressed me. Check out the can that looks like it's ready to melt with all the rounds put through it with the M249..
https://taskandpurpose.com/military-tech/army-next-generation-squad-weapon-m4-m249/
https://taskandpurpose.com/military-tech/army-next-generation-squad-weapon-m4-m249/