The issue isnt that US guns suck, its that they lowered the BR rating of all the other factions weapons to the point that what used to be tier 4 is now tier 2 wile silently (slightly) lowering the weapon damage wile increasing the weapon spread of the US weapons. At BR 1 USA you will be shot at by what used to be and should still be a tier 4 weapon.
The NEW DEVS hate USA, this game has lost all balance and realism when you play USA accept the underdog status and play smart. Perhaps the next batch of DEVs will be less intolerant of USA and adjust things to a balance. There seems to be a high turnover rate of DEVs each batch sees the world and the job in a new way. I was one of the original players in War Thunder I was in the BETA. Ive seen this company go thru a lot of changes.