A few questions before starting the second gun!

[Imkindofabigdeal]

Hey everyone,
I have a few questions before starting my second gun if thats OK:
1. Are vent holes on the combustion chamber any good? On my first gun, I drilled two holes that i didn't need, so i put wood putty, and PVC glue over it, watertight seal. It blew off after my first 2 shots, and after that, my gun seemed louder/stronger. Any ideas? How about on the barrel?
2. Can you make your own propellant? I use a mixture of Axe and Lysol Air freshener. Can you mix the two cans into one so you dont have to spray twice?
3. I was reading a lot about sparking. I am going to be building a cannon approx. 8ft long. The chamber will be 3ft and the barrel will be 5ft. It will be 6" for the chamber and 3" for the barrel. I will be using either a 650K volt stun gun or 2.4 million volt stun gun connected to about 3-4 spark points. Which one will be better?
4. Will the number of spark points be possible that i mentioned above?

Thanks so much everyone,
Ben

[saefroch]

The vent holes are probably losing you power, since some of your combustion gases are escaping out of them, instead of propelling your ammo down the barrel. It probably seemed louder because of the gases escaping out the "vent holes." It may have been more powerful if you were replacing more of the combustion gases with air before fueling.

If you're looking to upgrade propellant, build a propane meter.

Personally I'd go with more spark gaps.