Assuming you cannot unload the round by firing it at a safe backdrop, you use an attachment to your ramrod or cleaning rod called a worm. The worm resembles a screw. It drills into the lead of the bullet and allows you to draw it out of the muzzle. Take care since the firearm is still charged.
Depending on the bullet, 9mm goes slower than it, but a 45-50cal.
you shoot through walls. also, shooting people through windows works as bullet penetration
A few hundred or so, depending on condition.
It takes more than one shot, but if you have a Ma Deuce, hold down the triggers and sweep the gun from side to side, you can cut people in half with it.
54 is too big, trust me, however there are things (forgot what theyre called) that will be able to connect them together hope this helps!
barrett .50cal
about £678,900,46.58
bob the builder
No
Two in the head with a barrat 50cal.
It depends on local legislation
A couple of hundred meters.