The performance won't be too spectacular, as others have mentioned, but 20-30 yards is perfectly doable... Also, this post shows a number of the designs you are talking about, for a quick performance "run-down". Yes, those are some that I have gotten ideas from, my thought would just be to add a me...

Thanks guys for the replies, I've gotten everything together, But I believe the metering system must be off, I used the calculators on the Burnt Latke site, but I believe I'm over fueling. I Built it according the what the calculators say and I'm getting hit and miss ignition, I can hear the stun gu...

You're not going to get an enormous amount of power, combustions provide fairly low pressure and having a larger caliber usually makes up for that, but with a 1/2" barrel it's going to be quite limited. Consider downloading HGDT to estimate performance and play with the variables. Note that a coppe...

Ok, my plan is to build basically a propane fired musket, 36 inch long 1/2 copper pipe as the barrel, and 2 inch pvc chamber, I have an old stun gun for ignition, and I ran by Radio shack yesterday and bought a fan that will fit in the 2 in pvc pipe. I went on the burnt lakes site and their calculat...