small breech loading gun mounted on homemade tank

[Runningman5]

[youtube]

After searching the internet and not finding what I wanted; I built this cannon for the tank I am putting together. Has anyone seen anything like this? this is the first prototype that I put together and I was wondering about upgrades. more videos once I build some ammo.[/youtube]

[Doctore]

Looks good

What about range?And if you can post pictures of your tank when you finish it.

[Labtecpower]

[youtube][/youtube]

Nice I like the tank style 360 degree travel.

I see you use propane as propellant. Do you meter it ?

Also, according to other members, adding a chamber fan will increase performance noticeably. It will probably have trouble with your loading system however.

[wyz2285]

I have a friend that's buiding the same thing but he uses hydrogen and automatic reload. Any way very nice

[cammyd32]

That is painfully epic. I look forward too seeing it when it is finished.

[pipeboyswe]

Wow that looks awesome! What are the specs of the gun? barrel length etc, etc.

[Runningman5]

the barrel is a 2inch piece that's 44inches long. it's volume is about 1-1 with the combustion chamber. I have heard that the ideal ratio is 1.5-1, but I have been getting more than enough power with the current barrel. just the other day I launched a lemon at least 180yds uphill (not entirely sure cause I couldn't see the landing point).
the Propane has a one-way valve attached going into the combustion chamber, had to build it myself. for the breach I used a threaded end cap and cut off about half of the threads and ground down the rest. the whole door assembly is something I welded up. the ignitor is a rewired stun gun (fairly easy to do, but make sure everything is properly insulated!!!)

Pics and more vids soon

[Runningman5]

slideshow of pics showing new ammo:


Vids of new ammo:
and

[warhead052]

If thats an airsoft tank, I would suggest NOT using that ammo. Just for safety reasons. Just try a paper towel wadding, then bbs and then more paper towels. Then fire away.

[cammyd32]

That is a point, if you hit someone with that not only will it get them out, it will knock them out.

[warhead052]

Since it goes through plywood, it will kill them. Unless its a 2liter bottle airburst shell, I don't think its safe to use.

[Runningman5]

Yeah, I kind of figured that something that could put a nice round hole in plywood is not something that I want to shoot at people. considering the power that I am getting I don't want to shoot anything at anyone with this gun. I may try making a lower power version; with a 3inch combustion chamber or something. in the meantime I will just attach one of my airsoft rifles, that was the original idea anyway. Definitely going to keep the cannon for messing around though.

[warhead052]

Well, using a nerf football or something would work, but be sure to tell everyone to watch out for it. Call a 30 foot radius "kill" zone or something for the foot ball.

[Runningman5]

for target practice I marked out a 15ft circle around the plywood, it was a pretty big circle. from 150ft I was able to get 2/3 shots inside the circle, so 30ft might be a bit too much. I am hesitant to try nerf footballs because of the price, anyone know where I could buy them in bulk? otherwise they're like $8 each

[warhead052]

Try ebay, or try the paper towels and bb rounds.