How do I get my Weatherby auto-loader shotgun to fire semi-auto?

Pull the trigger again. But it sounds like you are having problems with it ejecting the spent shell. Is it a SA-08 made it Turkey? If so, that is a common problem. Run 4 or 5 boxes through it and see if it starts working. I guess they need polished some to operate as advertised.

I have an old semi made by another company. On mine there is a little lever on the right side of the gun above the trigger. When it is in one position the spent shell will not eject from the chamber. Flip it the other way and it goes semi. My gun is about a 1945 Winchester. I believe the lever just disengages the extractor. Your gun may be totally different. But it's worth taking a look.

First don't pull the trigger until your ready to fire... that said, I have dry fired shotguns many times and never broke them. You shouldn't dry fire rim fires because the firing pin strikes the rim of the cartridge and can strike the hard steel of the barrel instead of the softer brass metal of a cartridge. Now center fire cartridges (which is pretty much everything bigger then a 22 now a days) you don't have to worry about that. In the military we dry fire weapons all the time, from 50 cal, 240g 249 to our m16, we train/practice by dry firing. Last thing ALWAYS DO A SAFETY CHECK before dry firing your weapon. Have fun and be safe exercising with your 2nd amendment right.

did you try different ammo at all? This sounds like a case of insufficient power to cycle. Try a heavier/hotter load and see if that works. such as if you were using skeet loads bump it up to game loads or even pheasant loads. Some autoloaders can be a bit finicky on ammo too. Even a different brand of the equivelant type can make a difference.

it could be the ammo. disassemble and clean / is it gas operation make sure gas ports are open and all moving parts are clean and lightly oiled /if recoil operated it could be a spring problem/ when you disassemble check the friction ring they go two ways and turning it may solve the problem/ get high brass max loads if they work /go do down to lesser loads. Jesse

flip the selecter switch to three round burst then to single!