Hybrid Testing
Here you will find various hybrid testing.
03/14/2004
The setup for testing looked like this:
Click for bigger pic
As you may guess, there was quite a bit of setup. It was about 50 Degrees Fahrenheit outside, but the wind was very strong. Due to the wind, testing was brief. Future testing will be more complete.
I used my hybrid for testing, it is a 2700 ml (~165cu in), sch80 launcher. The chamber is made of 3" sch80. The barrel is 84" long, made of sleeved 1.5" sdr21. The ammo was golf balls. Every time the golf ball went into the canvas filled bucket, the bucket was violently knocked to the ground. You can see the bucket tipped over in the above setup pic.
The first thing on the agenda was to see how fast a golf ball would actually go. As I mentioned before, the wind was very bad, so I decided to test a 3x and a 6x mix. The data is far from complete, but incomplete data is better than no data. The first shot was a 3x 3atm mix (will be referred to as a 3x mix). The 3x mix seemed much more powerful than a regular combustion or pneumatic. I was surprised to see the chrony! It read 740.7 fps! If you can imagine the mass of a golf ball, this is pretty amazing! Keep in mind the gun was not built for breaking the sound barrier or anything of the sort. I could easily double the barrel based on past experiences and the sound of the launcher. Only one test, so, as I said before, very incomplete results. Here is the pic of the chrony:
With the 3x chronied, I decided it was time to try a 6x mix. For some reason, my burst disks were not cooperating, they would blow out and I would record 300-375fps with a pneumatic launch. Not overly impressive, but still neat.
Finally, after messing with burst disks and such, I got a successful fire. It was powerful, but very disappointing. The reading only said 775.7fps. I took off the cam lever coupler, and saw what had happened. The tinfoil had been sucked back into the chamber. I believe the thicker burst disk I tried was too thick, causing a vacuum effect soon after it burst. I know the 775.7fps measurement does not show the power of a 6x mix. It is my belief that that shot was not an accurate representation of the actual power of a 6x shot.
After the 6x shot, I looked at the spacer ring, which sets on the male piece of the cam coupler. It was blown in half. Its purpose is to allow the coupler to clamp tighter, and hold the burst disks tightly in place.
More testing is needed, and will take place when it gets to be nicer weather. It was good shooting weather, but not good testing weather.
Why testing in march in Iowa can be a bad thing:
This pic was taken two days later. The snow, all 9 inches came in
about a 18 hour period!