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JDP's combustion cartridge prototype
Posted: Sun Feb 07, 2010 3:08 pm
by JDP12
Well going off of JSR's efforts I've decided to make my own prototype.
It's 4" of 1" PVC, I have to let it cure and then add electrodes.
If I am happy with it I will make it without the endcap and cast the end with epoxy so its one smooth cartridge.
as You can see, I've decided to just go with 1" bore, same as the cartridge for maximum power according to HGDT.
You can see what it predicts below. Testing will come soon.
Watch this space
Posted: Sun Feb 07, 2010 3:27 pm
by jackssmirkingrevenge
Looks interesting, are you going to try and make it eject though? with barrel and cartridge diameter being equal I wouldn't be too optimistic about that.
Posted: Sun Feb 07, 2010 3:56 pm
by JDP12
No plans for ejection atm, if this works im going to make a double barrel shotgun (sawn off of course).
Then a revolving shotgun,
both based off of borderlands guns of course.
Posted: Sun Feb 07, 2010 4:18 pm
by spudtyrrant
JDP12 wrote: (sawn off of course).
i think you mean sawd
Posted: Sun Feb 07, 2010 4:32 pm
by jackssmirkingrevenge
In that case you should have a workable project, cartridge power is irrelevant to its function. Good luck
i think you mean sawd
The correct English term is "sawn-off", but since when did you yanks care about correct English
Posted: Sun Feb 07, 2010 5:03 pm
by Ragnarok
spudtyrrant wrote:i think you mean sawd
I think
you might want an "e" in "Sawed".
And as Jack says, "Sawn-off" is entirely acceptable.
In the end, this forum is full of different variants of English - you have to expect different words for the same thing, or different meanings of the same word.
There are many cases where I have to overlook words that are considered perfectly acceptable in the US but which are highly offensive in the UK.
Posted: Mon Feb 08, 2010 12:07 am
by Marffy
this would be awesome if it went in a huge side-by-side double barrel. i would think the layout would be good to.
Posted: Mon Feb 08, 2010 1:00 am
by JDP12
Well have to see.. Im gone for 15 hours aday right now.. So i dont get a whole lot of time to work on my projects but im doing the best i can.
Tests will come soon with a 20" barrel
Posted: Mon Feb 08, 2010 10:03 am
by iknowmy3tables
wait but those HGDT results only 178fps on a small caliber spudgun, if your fine with that I wouldn't start working on auto ejection/loading until there's power to spare but the idea of a break open shotgun is sounding pretty apealing
Posted: Mon Feb 08, 2010 12:54 pm
by JDP12
Yea, the velocity doesn't appeal to me too much.
Depending on how testing goes I may slap a 3/4" or 1/2" piece in there and try that.
178 fps is pretty weak i'll admit, i'm looking to at least equal a paintball gun in velocity and ft/lbs (10 approx).
So if i could get 280 fps and at least 10 ft lbs with a .5" or .75" barrel I would definitely go with that.
Tonight I'll be adding electrodes and gluing a coupler to a barrel so I can get a few tests going.
First up obviously is a double shot gun. Something with one of
these suckers on it would be pretty damn sweet... homemade of course.
more information...
If I don't go with a borderlands style gun after a double shot....I'd prefer to do a revolver style gun as per borderlands, but If i don't....
This would be pretty sweet..
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Little update-- After fiddling with HGDT i found my barrel length is TOO long, which is a slight issue. fiddling revealed I could get 213 fps.
Also I have an idea for getting more power out of it, if I'm not interested in getting ejection/blowback...
Will be posted later
UDATE 2: decided to slap a 3/4" piece in there and make it that calibre as HGDT predicts approx 245 fps with a 10 gram projectile and only a slight difference away is 1" bore, plus by choking it a bit it may have more potential for blowbak if i ever go that route. i have mostly everything glued up, curing.
Pictures tomorrow
So we'll see...
Posted: Sat Feb 13, 2010 3:39 pm
by iknowmy3tables
if you need a certain barrel length for aesthetics you can use a fake larger diameter barrel.
that's probably a good move to size the caliber down I can't imagine a efficient combustion made from a straight pipe where only 1/6th of the pipe is chamber. it should also be easier to make an integrated silencer because I imagine that there will probably be a part that you will put the cartridge into that will be made with 1.25" pvc and aesthetically it you can extend that 1.25" pvc to wrap the rest of the barrel in front of it and there should be enough plenty of space for a muffler between the inside of the 1.25" pvc and the outside of the 3/4" pvc, unless you want a silencer for some water-cooled machine gun look
Posted: Sat Feb 13, 2010 3:40 pm
by iknowmy3tables
DELETED duplicate post: sorry I accidentally resubmitted when the page wasn't loading for a while so my reply above got sent twice
Posted: Sat Feb 13, 2010 7:40 pm
by JDP12
Sorry for no updates ive been way too busy lately.
I do have it all epoxied up with 3/4" inch, but havent been able to test it. I will be sure to post results when i do
Posted: Sun Feb 14, 2010 2:14 pm
by jackssmirkingrevenge
JDP12 wrote:
That's definitely a project on the drawing board
Posted: Sun Feb 14, 2010 6:28 pm
by JDP12
Indeed......
Hope to be testing soon... Curse you school