what weapons would you like to see already existing or a concept you would like to have

honestly I think would be neat to have a water gun jump in a lake for a couple seconds to fill it and then use it to short circuit robots (by hitting very specific spots where water could leak into their circuits) and then have it be like the only weapon you could use against children and towns folk with out killing them (tho 5% chance they get pissed off and blow your head off 90% chance of them yelling at you 5% chance of them liking it)

so what weapons would you like to see in Fallout 4

For Fallout 4 I would like to see some more imaginative stuff. Like that water cannon you mentioned.
Rad guns that can kill people by giving them radiation poisoning etc.
More Two-Component weapons like the C4 would be nice.

I would like to see a better sniper rifle with decent zoom range, and they could add a better range of pistols like an M1911a or Desert eagle. They could even re introduce the schematics to build your own weapons.

Desert Eagle. The 10mm pistol is invalid.

Oh, and the AK-47 would be nice too.

In all seriousness, there's a forum for Fallout 4 in the Fallout Series Discussion, so this kind of thread doesn't really belong in the New Vegas forum.

http://www.gamesas.com/topic/1376878-real-world-weapons-youd-like-to-see-in-fallout-pt3/

That is a topic for real world guns in fallout 4.