No
NO! This is EXTREMELY dangerous!
You could eaither shoot dove with a 20 gauge shotgun or a 12 gauge shotgun. You should also use a bird shot shells
Yes, shorter shells are no problem.
yes
No, you can not shoot anything but 12 gauge shotgun shells through a 12 gauge shotgun. Never use any ammunition other than what the firearm was designed for.
Yes, you can shoot 3 1/2 inch shells in an Elgoibar double barrel shotgun if the shotgun is specifically chambered for that length. However, if the shotgun is only chambered for 2 3/4 inch or 3 inch shells, using 3 1/2 inch shells could be dangerous and potentially damage the firearm. Always check the manufacturer's specifications and recommendations before using ammunition that exceeds the chamber's designated length.
The length of the chamber in a 2 3/4 inch chambered shotgun is 2 3/4". The longer 3" shotgun shells will not fit in the chamber, being 1/4" too long. You can shoot 2 3/4" shotgun shells, of the correct gauge, in a 3" chambered shotgun.
Not recommended.
Yes
Any modern ammo should be fine. Your barrel should indicate whether you can shoot 2 3/4 or 3" shells. You may want to consult a gunsmith to see if you are able to shoot steel shot through your barrel or not.
A 41 magnum caliber revolver will shoot 410 gauge shotgun shells but is not recommended. The shot will lead the barrel rifling. There are also adaptors you can put in a shotgun that allow you to fire pistol/rifle ammunition.
A 12 gauge shotgun cannot fire 20 gauge shells.