This is my "little project" that I've been working on for the last few days.
Very much inspired by JSR's experiments which were "knocking on the door" of mach 1.
Specs;
Barrel: 36" of 9/32" .014"wall brass tube
Chamber: 6" (interior length) of 3/4" Type M copper
C:B of 1.5:1
Co-axial piston machined from nylon, with a teflon sealing face and floating o-ring seal
Pilot assembly: "Borrowed" from my copper gun. Features a modded blow gun, and an improvised probe style fill.
I have been using my home made stirrup pump with this thus far. Reaching pressures of 400psi.
I am using .12 gram airsoft bb's
According to wikipedia, the speed of sound in air @ 20C is 1125fps.
Edit: And according to my chrony (used properly this time), I'm not there.
A peak velocity of 1059fps was recorded for the airsoft bb @ 5 feet from the muzzle.
Posted: Mon Dec 01, 2008 9:56 pm
by SEAKING9006
Can't wait for a confirmed >Mach 1 shot. Tough, wouldn't it be better with a bigger chamber and longer barrel? (Just guessing)
Posted: Mon Dec 01, 2008 10:31 pm
by Ragnarok
I'm getting a dead result for the video link, but that might be because Youtube's about to undergo maintenance.
I wouldn't personally call this a mini, too long in my opinion - I think of it more as pistol sized, but if you prefer...
Looks nice and shiny. What range were you shooting that target at? 'Cos that ain't a bad group. (EDIT: Saw the video. This last comment no longer applies)
Posted: Mon Dec 01, 2008 10:40 pm
by Davidvaini
you should try to shoot some .20g bbs.. id really like to see the fps difference at such a higher end of the FPS scale..
Posted: Mon Dec 01, 2008 10:43 pm
by SEAKING9006
Better yet, throw some graphite-coated .40's up in that sucker.
Posted: Mon Dec 01, 2008 11:04 pm
by jor2daje
This is a beautiful gun just wondering what sort of lathe you used for the piston I really want to get one and Im not sure which are any good.
Posted: Mon Dec 01, 2008 11:29 pm
by Davidvaini
well the reason why I say .20 airsoft BBs is because that is the general standard for airsoft use.. not saying they would allow a 1200fps gun in airsoft.. but still.. nice to use the standard..
Posted: Mon Dec 01, 2008 11:50 pm
by FordGtMan
Dang, that piston looks nice. If you really want good power and accuracy take some .22 pellets and widen the flare with JSR's technique. I know this is a gun to shoot "airsoft", but it would be cool to see some power shots. Your defiantly going to have to do the coin challenge with this, although it wouldn't be a problem. Its tradition with all minis i create.
Posted: Tue Dec 02, 2008 1:28 am
by starman
Beautiful work as usual Gippeto. Simple and elegant. Looking forward to some operation/damage video.
Supersonic will be awesome... 8)
Posted: Tue Dec 02, 2008 1:58 am
by MrCrowley
Damn, people need to stop making cannons that I really like...I spend enough on this hobby as it is, and each time I see an awesome cannon, I want one just like it, but better
Great work again!
Posted: Tue Dec 02, 2008 2:12 am
by Davidvaini
MrCrowley wrote:Damn, people need to stop making cannons that I really like...I spend enough on this hobby as it is, and each time I see an awesome cannon, I want one just like it, but better
Great work again!
you should make a version of one of my BDC.. but make it better.. im sure you could make it better some how..
Posted: Tue Dec 02, 2008 2:47 am
by ALIHISGREAT
as i have come to expect from Gippeto, its a nice looking, well put together and good performing cannon
Posted: Tue Dec 02, 2008 2:54 am
by POLAND_SPUD
using helium on this should help to increase fps a little bit... it's just a suggestion
nice gun gippeto
Posted: Tue Dec 02, 2008 5:16 am
by jackssmirkingrevenge
Extremely well made, kudos
What's really interesting that you seem to be getting better performance than I was getting for a burst disk, using similar proportions, pressures etc. - could you try it out with the muzzle a little further from the chrony to see if it makes a difference?
I also second the suggestion that you should try some lead ammunition, get your hands on some medium weight 0.25" pellets
Posted: Tue Dec 02, 2008 6:14 am
by VH_man
that. Piston. Made. Me. Need. Paper. Towels.
How did you make such a bloody beautiful Item?
that and, For gods sake, Shoot a full can of seltzer water. You will be suprised. And catch it on video.
That and what is that fill thing your using? Ive never seen it before.