Long distance detection

Hello, I recently ran into a little snag in my paintball sentry gun project. I bought this range finder:


As i finished my project, i noticed, the range of detection was only...around 18 feet. Which is an insane distance to be shot with a paintball gun, I would really like to try for somewhere around 50 feet, but i cannot find any rangefinder that can go any bit above 25 feet, which is just not enough. I need a better range finder, or a better method...do you guys have any ideas?

i have a budget for the ranging system...around 150....the range is important because paintball guns can shoot fast...hard...and far...and 50 feet is a nice range..... also...the gun could kill someone if it hit them in the right spot...(spine, stomach) if it is too close...the range finder i have will only detect anything within 15 feet, which the right spot below 5 feet could be fatal, so i want a longer range to make the gun more functional. Also...the gun will be hidden...so walking super close to it will be common during a game...my code will only trigger the servo to fire the gun when something is further than 10 feet.

Have you considered using a separate rangefinder hidden in a different location that alerts the arduino when it is triggered?

i have, but the wire leading to it may cause a few problems:

1, stealth 2, Signal Strength 3, Someone Could get snagged on it 4, Aim. The sensor could get jerked, or worse 5, Portability, the gun needs to be able to be moved around.

I was wondering if anyone knows of a more powerful range finder that would be arduino compatible, i got 150 bucks to spend on it :-/

Well, im jst trying to be safe, And i forgot to mention, A regular paintball gun is going to be mounted on this, not a home-made gun, and i was just stressing a point, to kill someone with a paintball gun ud need to freeze the balls, then be 1 foot away from someones eye...and shoot.

So does anyone have any ideas on how i could get a longer range? 150 to spend on the ranger

Use a wireless system then. For $150 you can easily make a distance sensing node with an ultrasound sensor that connects wirelessly to the arduino connected to the paint gun. No wires, good portability.

The gun's aim will be fixed, yes?

Why not a "break the light beam" type trigger?

Small focussed IR beam transmitter (battery powered) at the far end of the gun's range, receiver 5' from the gun... hiding/ making safe 5' of wire shouldn't be too hard?

I completely agree with Richard on this.

What if the person at 150 feet triggers the gun and the unlucky one at 1 foot gets it on the stomach? or ... or ...

I wouldn't dare even to create a new directory with such a project unless in R&D of a defense company.

Yes I too think this project is folly. Are you 100% sure that your circuits won't be triggered by interference from say a passing motorcycle. That it is 100% reliable and that no one is in the way. I don't think you would get reliable ultrasound range finding over that sort of distance anyway.