SpudFiles

Hello, I am currently working on a semi auto marble gun, and I can't find a diffinative answer about what size barrel is ideal for marbles. I would prefer pvc, but I can make copper work if I have to.

Also, does anybody know if 1" NSF-PW (or pressure rated) wye's exist? if so does any body know were one could be purchased.

Thank you all for your help. I currently have 3 cannons that need to be posted. I will paint and take damage video / pics. when wheater allows.

This will be a cool gun when finished. It has a unique way of firing and is an adaptation of one of clide's valves. (that guy dose some nice work)

It will have interchangable barrels to shoot marbles at a higher psi (120-160) and a 1inch barrel to shoot power popper rounds at around 20-40 psi. (low pressure so my friends and I can plink each other without fatalities)

Well since marbles come in numerous sizes there really isn't an ideal barrel size. Take a marble to the hardware store with you and see what it best fits in. You might get some funny looks, but you will find your answer. Well in clide's (I agree that guy does do some nice work) inline piston valve he uses a pressure rated wye strainer. You can probably find them on ebay. Do the power poppers fit well in 1" pvc or do they need wadding? Can't wait to see your cannon!

The 1/2" marbles I have (not sure if they're standardized everywhere) fit EXACTLY into 1/2" Type M Copper pipe. 1/2" SCH40 PVC is marginally bigger but would work with a less ideal fit.

I think the marbles are either 1/2 inch or 5/8. Has any one used PVC for a marble gun?

The power poppers make a perfect seal in the 1" SCH 40. The balls are almost exactly 1" (I was quite surprised, usally things run smaller) and since the 1" pipe's ID is slightly less that 1" it makes a perfect fit. I will have seperate magazine and barrel. 1 for marbles, the other for the power poppers.

I work at a resturant and my boss bought one for me and the other prep cook, so on my shift I was harrassing the waitresses that came into the kitchen . the pre made ones are neat how they work, but performance is weak. they can only send the ball 20 ft. I shot myself at point blank when I first opened it to make sure I would not hurt any one, and I could barly feel it. The surprise of getting bombarded with 12 rounds within a couple of seconds is what causes people to stand still and cover themselves instead of simply catching the balls and hurling them back at you with twice the power of the gun. It is a novelty toy. I discovered the balls were a perfect fit when I was shooting the gun at my dart board and one of the balls richoched next to my 1" cannon. I picked up the ball and looked at the gun and an Idea struck. at first I thought the ball would not fit because it will rest on top of the barrel

I don't know much about PVC but I use 18mm copper pipe ( 16 mm ID) and it works great as a barrel...
well almost great... the thing is that 15 mm marbles I buy are about 15.5 - 15.8 mm, which gives a good tight fit... but there is like one or two marble in each 100 pcs pack that are oversized.. naturally when you get something that's bigger than the barrel you get jamms...

so my suggestion for you is -> buy several brands of marbles and measure them with a caliper first... I suppose that there might be a difference in size between different brands so take that into consideration...

first choose ammo that has consistent size, is cheap and easily available then choose a barrel... with semi you run out of ammo very fast so I'd say that ammo is more important becasue you have to buy a lot of it.. if you f*** something up you might end up with occasional jams or loose fit resulting in lowered performance