There's a lot of 'unstable' in the new Goliath gear, which is a 50/50 chance to blow yourself up every time the dice tell you to make an ammo roll!
The storm welder the new small guys carry seems to have a roughly equal chance of exploding the guys you point it at, or yourself, or both. Str 5, Rapid Fire (3), Unstable. So potentially putting out a huge amount of shots, but also really high odds of going boom yourself. Only 16" range with +1 to hit at 8", and the guys carrying it are BS4+ though.