Needs to be looked at by a gunsmith
Usually you fire the right barrel first. It's choke is normally a little open giving a wider spread of shot. You fire the second barrel which is normally a tighter choke at a target farther away. This tighter spread will be concentrated but spread because of the long range assuring more pellets hitting the target. Firing the right barrel at a greater range might have the target escape by having the shot pass by without hitting it because the pellets are spread too far apart.
The Browning M1919 can keep firing until the barrel overheats. It depends on how long the bandolier is, since it's fed that way. If overheated, it can't shoot and the barrel needs to be replaced.
There are a lot of possibilities here. Does the other barrel fire if you set the trigger for the other barrel? If so, you may be holding the shotgun too loose, away from your shoulder, or have too much padding on. The Baikal in ejector mode has to, upon firing, trip the ejector sear. If you hold the firearm too loosely, the ejector sear will not trip and the next barrel will not fire.
A rifle that has barrel removed- not likely. Revolver that has barrel removed- VERY likely.
When was the second fire at the whitehouse?
On the Baikal/Remington SPR 310 O/U, you simply push the trigger forward to select the top barrel, leave it alone to have the bottom barrel fire first.
No
no, because the air is what pushes the paintball out off the barrel.
It is when you fire the rifle or shotgun, but the projectile fails to leave the barrel of the firearm.
metal
The part which the bullet comes out of....
When the short & wad do not exit the barrel when fired, you have a squib fire, on any gun.