SpudFiles

Hello, i am in the process of making a Advanced combustion with a 30" long 3 inch diameter pipe, and a 2" diameter by 5 foot long barrel. I am using metered propane at 35 psi.

I was wondering how many fps i could shoot a 100 gram slug, and how many Foot Pounds Of Energy My Cannon Should Have?

Have you tried HGDT? It makes these kinds of calculations rather trivial.

If you used a 65 psi burst disk and 3 spark gaps, 3.5 oz projectile, 2" inch bore, it looks like you would be at 834 ft*lbs and velocity of 493 ft/sec. Rather nice c:b ratio of 1.12:1 as well.

starman wrote:it looks like you would be at 834 ft*lbs

That's almost the same as a three round burst from one of these, so be careful

jackssmirkingrevenge wrote:

starman wrote:it looks like you would be at 834 ft*lbs

That's almost the same as a three round burst from one of these, so be careful

That's also the range of force on one of my trip thunder golfball shots.

starman i thought you used propane ?

trigun wrote:starman i thought you used propane ?

I've used them both equally successfully. I switched to MAPP at the Christmas shootings and it offers a small but slightly noticable performance thump. You need a little more MAPP than propane...I just upped my regulator setting from 68 to 75 psi and that was about right.

so the mapp is better maybe i'll upgrade. I inspected your cannons farther and saw what you were talking about with the male to 4-2 reducer it looks so clean !