what would be a good alternative to a real gun?

I can't think of any. If you are in a situation where you need a firearm, you need a firearm.

Or you could hire SUPERVACA to protect you . . .

There isn't one. A firearm is one of the few tools which, when you need it, NOTHING ELSE WILL DO.

A flashlight is another of those tools -- sure, you can find "alternatives" but none of them are all that good.

This goes double for a firearm.

If you're talking about "What would be a good alternative to a real firearm FOR TRAINING PURPOSES" such as learning about muzzle control and practicing getting used to the four cardinal rules of firearms handling:

1) All Guns Are Always Loaded

2) Never Let The Muzzle Cover Anything You Are Not Willing To Destroy

3) Keep Your Finger Off The Trigger And Outside The Trigger Guard Until You Are On Target And Ready To Fire

4) Know Your Target, Backstop, And What Lies Beyond.

Airsoft might be a good choice for learning good habits which can translate to safe firearms handling.

If you're talking about "What's a good DEFENSIVE alternative to a real gun?"

There isn't one.

1) Pepper spray: Has about a 50 percent failure rate in real life situations. That, and with the wrong wind, you could end up incapacitating yourself.

2) Taser (REAL taser, not the contact stun-gun, but something that SHOOTS DARTS): Effective, but limited by the range of the tethers AND if your subject is wearing clothing which prevents contact from being made.

3) Knife: Requires you to be too close to use it -- remember, a dirtbag who has chosen you as a victim already thinks he has you outclassed, and if he's any quality of predator, he's probably right. Meaning you're pitting your skill against his -- it is likely you will lose, and even MORE likely you will receive serious injuries EVEN IF YOU WIN.

4) Contact Stun-Gun (What most folks CALL a "taser" even though it isn't.): Again, requires you to get too close, you have to KEEP contact in order for it to work (during which time if you DON'T keep contact, Mr. Bad Guy can keep hurting you or keep attempting to disarm you and THEN hurt you), and again, pits your skill against your assailant's, which, most likely, will be inferior.

This is not meant to be insulting -- it is meant to be realistic. Remember that an assailant PICKS YOU. How do you think he does that? By choosing someone he thinks he can victimize.

A firearm gives you two distinct advantages:

1) Distance

2) Disparity of force.

Meaning, a 79-year-old elderly lady can defend herself effectively from a 200-pound weight-lifting gang-banger with martial arts training WITH A FIREARM, with the lowest possible risk of damage to herself.

Meaning, you can safely engage an assailant at beyond a range where they can offset your defensive capabilities with skill. (Even Bruce Lee couldn't dodge a bullet, no matter what the movies portrayed).

A FIREARM is the only tool which is designed to, and does this task the most effectively.

There is no truly acceptable alternative. If there were, police would be using it as the pinnacle of their use-of-force continuum.

Instead of a firearm.

An Oxymoron.

And, what for? You mean a gun, like pellet/nail gun, or a firearm? For self defense? Pepper spray, eyeglass cleaner, Mace, Taser/stun gun.

Need more Data...

a homemade gun. there's load of manuals on the internet, some even published by our own government (for people too poor to buy real guns?)

I recall the law does allow for homemade guns - "personal firearms".

Obi Wan Kenobi

Pellet air gun

sling shot

snares

bow

A real big gun..

Two real guns.

The closest thing would be an airsoft or BB gun, they are almost exact replica's of well known weapons and function almost the exact same.

a body guard.Let him deal with the altercations.Pay him to take the hits for you.Good deal if you can afford it.