Get 200+ damage in one shot challenge bug

Hello, I played ShellShock Live today and I got over 200 damage in one shot a few times, but the game just didn't register it in the challenge. I am now at 131 even though my highest damage was about 280 in one shot. Please fix this.

 

Was the weapon that you used just a single shot with nothing else (So a sniper, single shot, grenade, etc) or was it a spread weapon (Three Ball, Tadpoles, Air Strike)? Cause I had this thought before since I wondered why I wasn't getting the challenge registered when I was using spread/multi-shot weapons until I landed a X2 crit sniper shot and then it popped up.

 

The achievement requires the damage to be dealt by a single projectile on a single tank. The only weapons capable of doing 300 damage with a 2x crit are sniper, arrow, bouncy ball, spaz, clover, shooting star, bfg 9000, nuke and jackpot, and the higher tiers of these weapons.

 

Okay, thanks guys. I did this with Grand Finale and a beacon and was wondering what is happening.