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A Good Day of Melon Shooting.Video Update.Truely Awesome!

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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Unread postAuthor: MrCrowley » Tue Feb 27, 2007 4:12 am

The chrony results also depend on PSI and chamber volume and Projectile weight/drag coef and barrel length. Oh and climate and tempreature.

Oh and it comes with all threaed fittings and machined piston that shouldnt fall apart.
You can compare one gun to another but its a bit different when the valve is on a totally different gun isnt it?

Maulers are also in a 2.5: tee not a 2".

Having the gun close to the chorny also affects results dramatically.

So this valve would also out perform a supah then? Why would someone spend $100US on a supah when they can spend $5 and melt some glue sticks? A Mauler also saves more air as it has O-Rings.
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Unread postAuthor: killagorrila99 » Tue Feb 27, 2007 4:14 am

So this valve would also out perform a supah then? Why would someone spend $100US on a supah when they can spend $5 and melt some glue sticks?

Caus there noobs. And I hate them. Alot.
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Unread postAuthor: rna_duelers » Tue Feb 27, 2007 4:46 am

People people,stop the bitching.

I will do some more Chronographing when I get the chance and try different methods to see if the muzzle 'blast' is effecting the reading.

Who is Sean?Is it BC Gort or who??Because gorts valves are machined with a wood lathe.Which is not the choice of some one after accurate machining.

There is also the satisfaction of making your own valve.Which I believe is as fun as shooting the cannon.
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Unread postAuthor: Insomniac » Wed Feb 28, 2007 5:16 am

Ohhh wow........ :shock:

That video is amazing! Pity there is no sound though...
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Re: A Good Day of Melon Shooting.Video Update.Truely Awesome

Unread postAuthor: killagorrila99 » Wed Feb 28, 2007 5:21 am

rna_duelers wrote: Thanks to Killa for Helping me getting this video up.Without him it wouldn't of been possible.Thanks.


Yay!
I got mentioned! Its time for a sexy party!
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Unread postAuthor: joannaardway » Wed Feb 28, 2007 5:47 am

Sean = Sgort. Sgort's full name being Sean Gort - I wonder how he got his username?

I don't really care about the muzzle velocity - the piccies and video are enough fun anyway.

Just to prove it to yourself - try again, but move the chrony back.
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Unread postAuthor: spudthug » Wed Feb 28, 2007 7:15 am

sweet gun and nice chrony reading but i tihnk it might be a little messed up cause u r definately getting some air coming out of the barrel...just move it back 6-8" or so and you will get a true reading....anyway nice gun and nice damage picks
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Unread postAuthor: jrrdw » Wed Feb 28, 2007 8:27 am

Get a smoker to fill your chamber full of smoke, then load and fire, the smoke that comes out of the barrel should tell you where the air woosh stops and that should be a good indacater where to set the Chrony. Or maby dry fire with talc powder in the barrel.

This is just a idea, i don't know if it will work!

Question -- Does the projectile start loosing speed as soon as it leaves the muzzle? Or does the projectile keep gaining speed for a short amount of time, then loose speed?
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Unread postAuthor: rna_duelers » Wed Feb 28, 2007 4:30 pm

What about the video?!?What do you think of it?

jrrd-I was thinking of just a dry fire,the water vapour is the culprit here(I think) so if I measure the vapour speed and if it is around the 900fps mark then I'm sure it is the vapour not the projectile.The projectile would start to slow down as soon as it leaves the barrel from air resistance nd many other factors...Ohk well mainly air resistance :wink: .

Joannaardway-Thank you for clearing that up about Sean.I will try a few methods to see if the velocity is acurate.

Spudthug-Thanks for the kind words,the damage was awesome.I'm definitly going to do it again.

Perhaps some of you should give the using of a water melon as a target its great fun.The clean up isn't though.
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Unread postAuthor: joannaardway » Wed Feb 28, 2007 5:06 pm

jrrdw wrote:Question -- Does the projectile start loosing speed as soon as it leaves the muzzle? Or does the projectile keep gaining speed for a short amount of time, then loose speed?


It should start losing speed as soon as it leaves the muzzle - but a foot of air won't have much effect on the speed.

A poor cannon with too much muzzle blast can continue to accelerate the ammo some distance after the muzzle, which tends to reduce accuracy and (surprisingly, but not with spherical rounds) range - because the projectile is now spinning, it exposes a more "resistant" flank that slows it faster.
Proper venting/porting can correct this problem.

This is loosely based on experiments that me and my brother did a while back. Adding a few inches of porting to a barrel can improve range massively.

EDIT: Could I suggest that a large plastic sheet placed under the "experiment" could aid in cleaning up any mess?
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Unread postAuthor: rna_duelers » Thu Mar 01, 2007 4:42 am

The plastic sheet would of been a very good idea but I was not expecting the Melon to explode like it did.What type of Porting?Could you go into a little more detail please as I am always after more range-But then again who isnt?

Ohhh I have added a new picture to the collection.Enjoy all.
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Unread postAuthor: joannaardway » Fri Mar 02, 2007 10:02 am

Venting/porting - as in drilling holes in the end of the barrel.

It's not much good for golfballs or other round ammo, but spud chunks go much further from a pneumatic with a few extra inches of ported barrel, than one without.
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Unread postAuthor: rna_duelers » Sat Mar 03, 2007 12:52 am

Ok thanks,I might give it a go on one of my other cannons.

Hopefully I will be Chronographing The cannon again,testing the 900fps reading from before.
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