Here is the full list of all 13 UBERMOSH Vol.3 achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
SCORE 400+, GUNNER CLASS MOD
SURVIVE AN EVENT, NO CLASS MODS
SCORE 400+, NO CLASS MODS
SURVIVE AN EVENT, KENSAI CLASS MOD
SCORE 400+, KENSAI CLASS MOD
SURVIVE AN EVENT, GUNNER CLASS MOD
SURVIVE AN EVENT, WARLOCK CLASS MOD
SCORE 400+, WARLOCK CLASS MOD
SURVIVE AN EVENT, CATALYST CLASS MOD
SCORE 400+, CATALYST CLASS MOD
SURVIVE AN EVENT, PSYKER CLASS MOD
SCORE 400+, PSYKER CLASS MOD
SCORE 800+