I think it's a good idea to inform local law enforcement of anything like this that you do. When I'm shooting video in a public place, where I'm staging a scene of some sort, (especially action,) I always tell the local police, and if possible try to have one present.
When you've got a guy running around with a blank firing gun, it's a good thing to have the police there to put people at ease so that minimizes the 911 calls, (plus, if the police are aware of the situation, the 911 call can be handled quickly with them saying, "yes, we are aware of the situation. They're shooting a movie there. There is an officer on site. It's not real. Thank you for your concern..."
If you're in a public place making sounds that are ANYTHING like gunshots or explosions, it's always a good idea. In McFly's case, the officer just laughed and drove off. Sometimes you get a more irate officer, who is annoyed at the initial panic, who will berate you.
As to the stand...
Buddy of mine made a couple for under 20 bucks out of PVC pipe and PVC Electrical conduit and about 15 3-way "T" joints that fit the PVC.
It stands about shoulder height, so it's great for standard height targets.
I thought I had pictures of the whole thing together, but I have it in sections. The base of the monster looks like this.
That center section is the 4 way electrical junction box. The outriggers are for stability, and there are 3-way "T" joints at the ends for weight. The blue bits around the junction box are PVC twist locks that screw into the junction box. The whole thing is held together by pressure and friction. So it breaks down easy.
Now this works as is on carpet and concrete, but for better base stability, you can use those standard, narrow little tent stakes in those two screw holes in the electrical conduit to drive it into the ground. I usually do this.
You put an approximately 4' section of the PVC pipe into that center hole in the conduit for your upright. This puts the target area just a little under shoulder height. Perfect for targeting, (your mileage may vary. You can lengthen or shorten the upright to suit yourself.) That top section is just another 3-way "T" joint with short, (I think they're about 3") sections of PVC pushed into them. It is on this, that you customize your target stands for whatever purpose you need.
For cards:
Just put clothespins in the PVC junctions and clamp cards in them. You can rotate the joints around as well to adjust angle, and you can put them in upright for sidearm and cattleman crack targeting, or you can put them in vertically for circus, overhand and underhand crack targeting.
If you're getting really fancy, you can set up a bunch of those little PVC junctions and do candle snuffing.
The larger sized Mennorah candles that you can find cheap at almost any grocery store work well for that, plus, they're just parrafin, so no colored wax stains on your fall!
All broken down into it's separate parts, you can fit the whole thing into a medium sized backpack, (minus the upright, and we're working on that with just putting a two-way junction collar in the middle of the upright.)
Before you ask, it's not incredibly solid. If you smack the target stand with your whip, the stand WILL fly apart.
Believe it or not, this is a GOOD thing. When you're throwing a pretty powerful kinetic wave down a length of leather that is getting more and more concentrated as it rolls down the thong, the last thing you really want is for that energy to dead end in the Fall. Most folks I know who build target stands use microphone stands and big clamps, and then cover the stand over with foam to absorb the shock from mishaps the whip, otherwise their falls get torn apart. This makes it bulky, and hard to adjust, (invariably, the pressure locks get covered in the foam somehow, and you have to pull it aside to make adjustments.)
With this, the energy hits the PVC and blows it apart, dispursing the shock. Remember, the goal is the target, not the stand. If you hit the card right, you'll cut right through it without disturbing the stand or any other target mounted to it. And there is something incredibly motivating about putting the bloody thing back together when you smack it by accident. There are pieces that wear out, (I've had to replace the blue twist lock piece that connects the upright to the base,) but as you can see, the whole darn thing is completely modular, and the parts are CHEAP. Pick up several extras, and you're good to go. They're also standard and easy to find. Just go to Lowes or Home Depot if you need to do repairs.
It gives you instant feedback as to how hard you were cracking, and how hard the whip hit the target, so you can learn control that way. Something that I think makes you that much better when you decide to forgo a PVC target stand for a human one.
This is just my buddy Bryian's prototype: Version 0.9 Beta. We took it to Annie Oakley and Canasta thought it was pretty cool and gave us some ideas for version 1.0, and we'd welcome any thoughts anyone else has.
Happy cracking! Hope this helps!
Anyway, I'm off to a machine gun shoot in Kentucky! Have a good weekend, folks!
I need to learn more things to do.