just does not seem to fit on a pinball forum for all ages, much like Pinside was scrubbed of boobs a few years ago I dont think it belongs on what Robin has said is a family friendly push for the site.
I will say it is pretty odd to be wanting to trade weapons used for killing to get pinball machines for playing.
I suggest you go to a Weaponside or Gunside to sell your guns and then just buy the pins you want.