I recently bought a used over under with double triggers. First time out shooting, I noticed that the rear trigger would only fire when pulled first.
I contacted the seller and he told me that older guns like these sometimes have a "firing order" ie you have to pull the front trigger every tike.
Now I am by no means an expert on shotguns but I checked with a couple gunsmith buddies and they had never heard of this. The gun in question is a 1950s bBeretta. Has anyone ever heard of this on a shotgun?