There's not a ton written about this that I can find, but cracks are appearing in the US military's plan to replace the M4 with a heavier battle rifle designed to defeat body armor. Sig Sauer, which also holds contracts for the current generation pistol and LMG, won a contract last year to also provide the US military with a new rifle. This rifle is to be called the XM7. The civilian equivalent is the Sig Spear. Calling this thing an assault rifle is a bit of a stretch, as it is very heavy and uses heavy ammunition. It turns out that the rifle is failing to penetrate modern body armor without the use of tungsten bullets. Also its reliability is questionable.
The thing is there is already a gun (the SCAR-H) that does what the yanks want in terms of firing a heavier round for armour penetration, is already combat proven in yank special forces and is almost 2lbs lighter than the XM7. But because it uses already existing ammunition, and because it's not made by Sig (the company with all the contracts) the government rejected it lol.
Is that what happened? Always wondered why that big neat-looking rifle I used to see in all the media just suddenly fell off
Yeah it got rejected from the program. See my other comments in the thread for the whole story