For "no bang" issue do simple "pencil test"
Use regular H2 pencil with rubber end.
Cock the hammer, point the muzzle up, put the pencil into the barrel with rubber end then pess the trigger.
The pencil should jump at least 1 inch.
However be careful, sometimes it jumps few feet

You can also press firing pin from back and check if the tip comes out from the channel.
Now you will have some idea what may be wrong with pistol.