I solved this issue by having my character specialize in knives. No issues with permits, noise, etc. Vampires in the modern nights would also be wise to do what smart civilians do when someone opens fire on them...run away and live to fight another day. There's a massive advantage to someone choosing where and when the gunfight starts. If your characters aren't the ones choosing, they're probably going to be the ones losing, whether by getting knocked into torpor or creating a big masquerade breach by shrugging off a bunch of bullet wounds in public. (The myth of someone on pcp just shrugging off gunshot wounds has been thoroughly debunked by all the videos of gunfights in public. People know that gunshots bleed a lot and people who eat 3+ 9mm rounds aren't going very far)
Should be noted that Banu Haqim can do rifles and set up ambushes because they can mute the sound of the gun shot. NOTE: the bullet traveling supersonic will still make a lot of noise once it leaves the area of silence, but it will be next to impossible to pinpoint where it came from with the initial gunshot completely silenced. ST note: if characters want to use subsonic rounds with a suppressor, they still make a lot of noise without the Banu Haqim power to mute all sound. Also, subsonic rounds have between 33-50% less energy than supersonic rounds, so you need to reduce the damage they do. .45 acp rounds are already subsonic, so suffer no reduction in damage.