Warning shots are NOT recommended ....
http://blog.robballen.com/p2853.post
Legal issues aside, warning shots are a bad idea for several other reasons.A warning on warning shots John Gutmacher explains
Got an email today, and I thought I'd better give you a quick warning about warning shots -- just in case you haven't already read my book, and don't know. A warning shot is always the "use of deadly force" in Florida, and therefore unless you can lawfully use deadly force at the time the warning shot is fired -- you could be arrested and charged with a felony (normally aggravated assault) that carries a twenty (20) year mandatory minimum sentence vs. the three (3) year mandatory that would normally be the penalty if the firearm was not discharged. In essence -- if you decide to fire a warning shot -- you must have had the option to legally shoot the assailant -- but opted on a less drastic measure. Sometimes a very tough choice -- but if you don't know how serious the repercussions of a warning shot can be -- you could get in one heap of trouble!
For starters, you are responsible for the projectile. Who actually aims their warning shots at something they are willing to destroy as well as knowing what lies beyond it? There's been quite a few stories of people killing others unintentionally when firing a warning shot.
Another drawback is ammo loss. Life isn't the latest shoot 'em up video game, reloading involves more than just touching the ammo icon. Plus, in real life, few people have thousands of rounds of ammo on their person (this guy probably being the exception to the rule). Even with high capacity magazines, there is very little room for waste. A warning shot uses up a round you might need later.
Finally, in some instances such as nighttime and inside a closed area, a warning shot can disorient you with the noise and flash. No need to do that until absolutely necessary.
If you're concerned about being able to deescalate the situation without lethal force, you need something besides a warning shot. At least here in Florida, you can see the warning shot = deadly force. For home use, I suggest a pump action shot gun. Nothing says "you're in the wrong house, bub" than the loud CHACHUNK of a round being chambered. It lets the perp know you're armed without wasting ammunition or endangering others with an unaimed warning shot.
These, of course, are my opinions and do not necessarily reflect reality. Your opinions are greatly appreciated.