FTF... now what?

[new_shooter]

I've not done a lot of shooting, as this question will possibly make obvious. This is something which, in the past, I've left to my more knowledgeable friends to handle. But now that I've entered the ranks of gun owners I figure I should know what to do in advance. So here's a hypothetical situation (modeled a bit after what happened with a friends AR in the past):

I'm on the line, firing a semi-auto AR. First 3 rounds from the magazine were normal, but the 4th fails to go 'bang.' On examination the round is found to have mis-fed, twisting the bullet in the casings mouth and denting the casing on the chambers lips.

2 main questions:

1) What precautions should be taken re: removing the failed cartridge? Cartridge is jammed in place, so it won't just fall out.

2) Once the cartridge is extracted, what to do with it?

And in both cases, what is the reasoning behind the suggested actions? (I like to know the theory behind the procedures)

Thanks for any responses.

[P-11 shooter]

we have buckets on most of the ranges for duds and mis-fires. Witrh modern ammo it's my understanding if it doesn't go off when the firing pin strikes it it's not likely to go off at all. Just throw it in the trash can.

I did have some old 8mm ammo that would hangfire. I think the modern stuff is pretty safe.

P-11notanexpertSHOOTER