The charge mechanic is a deliberate design to prevent quick-scoping OHKs in certain shooters.
The way the snipers charge in this game are tied to game balance (starter sniper charges fast to 3x DMG, but loses the charge if held for long, second sniper charges slow, but can be held forever and does 4x DMG...).
So yeah, your problem is not a problem, just the way they designed the weapon.