The first modification I did after exploring this site was to modify a Nitefinder I had lying around. I did the typical things: removing the Air Restrictors, replacing the springs with two stronger ones, and giving it a brass barrel (with a breech, but that's a different tale for another day). But I didn't see that much of a range improvement, and I was disheartened.
I later realized the reason was that I was trying to use a 2-BB stefan in a Nitefinder, which was probably a little to much weight for the thing to take. But, at the time, I had no idea. So I looked into other options.
One thing that occurred to me was that, if I could get more of an air build-up behind the dart, I'd get more power and distance. But my darts were already very tight in the barrel, and I couldn't think of anything else to do...until I remembered expanding slugs in firearms, and how the back of the bullet expands to fill the grooves in a rifled barrel.
So I decided to do something similiar. Here's the process I used:
Materials Needed (these should seem familiar ):
-Foam Backer Rod (because it fit my barrel perfectly, I used 3/8" FBR)
-BBs (I don't have the exact weight here, as the box was discarded. They are standard steel BBs, as far as I know)
-A Sharp Knife
-A Belt Sander (optional)
-Make your stefans as you usually would. Mine were approximately 1.25" in length, and each had two BBs in the weighted end.
Now comes the new part
-(Optional Step) Get your Belt Sander, and sand down the tip of the glue and the top portion of the dart, rotating the dart as necessary to get an equal removal of material from every side. The end result (sorry for the lack of pictures, but my computer is a piece of garbage and doesn't recognize my camera software) should look something like a traditional bullet: wider at the base, narrower at the tip. Use either the sander or a knife to remove the frayed edges. This isn't mandatory, but I've found it helps darts fit into breeched brass barrels: where the dart would normally require some twisting to fit, it now slides right in. I've also noticed a slight accuracy increase on the darts I do this to.
-Take the finished dart and, using your knife or other cutting implement, cut a single line directly in the middle of the unweighted end. The depth of this cut should be approximately half of the length of your dart. Then do the same on the other axis, resulting in an cross-shaped cut on the bottom of the dart. I've also had luck with a three-cut pattern, with each spoke of the cut at a 60 degree angle.
Now, I suppose you're all wondering (unless you already can predict) what this will do. When the gun is fired, the air strikes the back of the dart, forcing the cuts open, and thus flattening the divided sections of the dart against the sides of the barrel. This makes the dart's grasp tighter, but not tight enough to impede it's progress. Which, of course, means a greater air build-up before the gun fires, translating to increased power and range.
My Nitefinder was firing about 30'-35' with the original 2-BB stefans, but when loaded with the exact same stefans (now with the Expanding Cuts), it was reliably hitting 65'-75' with alarming accuracy. The same happened with my Big Bad Bow, and a second Nitefinder. The increase in power is also staggering: before it felt (at 15') like getting hit with a normal dart. Now it leaves a sizable red mark and stings a bit.
Admittedly, this might be a fluke, or it might be compensating for my rather average stefan-making skills, but I felt that it might at least prove useful to someone, somewhere.
Edited by ToxicWaffles, 07 May 2009 - 01:11 PM.