100lbs Heavy Bag story/question

Well, in an apartment, you don't have a lot of options. I'd actually be surprised if the owner is going to let you put a bracket into the ceiling, but maybe it's possible. Although, no matter what you do, the vibrations and noise might very well end up disturbing your neighbours.

Anyways, you have three options: the ceiling, the wall, or a free standing unit. The ceiling bracket and wall brackets obviously both require a sturdy rafter or wall stud to tap into. With both, a little trick to cut down on some of the vibration and noise is to not attach the heavybag directly to the bracket, but run a small piece of heavy duty cable down from the bracket (putting loops on both ends) and then hang the bag on the cable. The cable absorbs some of the impact and less is transferred directly to the rafter or stud to keep the vibrations down. Others have had some success putting a heavy duty spring inbetween the mount and the bag as well.

I'd suggest that your best option in an apartment building though, is a free standing unit. It won't destroy the ceiling/walls and give you some more options as to where you can put it. The downside is that the vibrations will be transferred through the floor so if you're on the second floor or have someone below you, it's probably going to bug the crap out of them.

I've hung a heavybag in a few different houses and according to my wife the best way to hang it is outside in the garage where she can't hear it and it doesn't shake the house apart. It is possible to dampen the noise/vibrations, but it takes a lot of bracing which you probably aren't going to be able to do in an apartment.

There are other options for wall mounts/ceiling mounts/stands than what I linked to above. Just visit the How to Box store and type heavybag into the search box for a wide variety of options.

Ha, i noticed this post was months ago. Have you had any noise complaints from your neighbours?
I used to have a punching bag in my house, and the vibration/impact around the house was similar to a 12 inch sub woofer pumping out some heavy beats.
If this post was more current, I would, from experience (and as an apartment dweller) strongly recommend NOT mounting a punching bag in your apartment.