A gun for picking up guns.
You point, shoot, it picks the gun up.
Not like the TK Wielder, because this would put the gun in your inventory.
Possibly with the power to knock guns out of enemy hands/steal enemy weapons.

Mostly for use with large actors, as for me I normally end up crushing small objects.

like this?

I mean, more a remote-pickup.
If the shot hits a gun, the gun is placed in your inventory.

grappling gun. Solved.

I tried that with the grapple gun, doesn't seem to work.
You can use the telekinetic wielder to get it.

I suppose this could work rather easily.

A simple gun that shoots a pixel with a Lua script that does this:

1. Check for an actor nearby (shooter) and assign him as the parent/user.
2. As the pixel flies, make it check for items in a small radius (a range of 20-30 pixels should be enough) or use an MO ray (I have no idea how those work).
3. If the pixel finds an item within this range, put it in the parent's inventory.