Make sure you have binded e to next weapon variant and q to previous weapon variant so you can still pboost swap and shotgun swap.

This is a melee weapon, with its damage multiplying by two as you gain momentum, which it can multiply up to two times. In short, a dash will get you one multiplier instantly, and a dash jump, dash into bhop or slam will get you to max damage after about half a second. You can hold the fire button to charge a punch, and I recommend doing so otherwise you will likely miss since it has a one second long wind up before charged enough to punch.

It does about 2.5 damage per hit so that means a full swing does 8 damage, enough to instakill a maurice and nearly wipe an entire phase off a swordsmachine.

As you can see here it can do more damage than the railcannon.

You should never make the blue one an alt.

It makes core ejects rise in an arc instead of completely straight, so it's easier to be intercepted by tall enemies and harder for you to hit. I personally recommend the red as it lets you keep the powerful green shotgun while weeding out the weak red one, but the green jackhammer lets you cause red explosions. Note that more pump means more damage, but it's quite minor as seen in the gifs.