Yep, you can make bullet traps.
If you're going to use it for anything larger than .22, it should be of 3/8 inch steel plate, and anything over 9mm 1/2 inch.
I'll be danged if I can remember offhand where there are posted instructions... although it'd most likely be a project for a local welder.
As for noise, well... you neighbors are GONNA notice anything over a faint pop and probably call the cops!
I KNOW this to be true.
Use in the basement and close all the doors and insulate the windows, maybe???
Bullet traps aren't really that expensive... try www.cabelas.com and check. They usually have several varieties.