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Posted: Sun Oct 28, 2012 4:07 pm
by POLAND_SPUD
lol alcohol Y U make me forget things?
since it worked well it seems I give good advices, don't I ? heh
Posted: Sun Oct 28, 2012 4:16 pm
by sharpshooter11000
Haha
Looks really nice JSR, loving the carbon fibre! I'm guessing the metal parts are epoxied in and you didn't machine threads in the CF?
I wonder what the performance increase would be if you used .177 pellets... (With a .177 barrel, of course)
Posted: Sun Oct 28, 2012 4:34 pm
by POLAND_SPUD
I wonder what the performance increase would be if you used .177 pellets
there won't be any performace increase to be honest
heavier ammo equalls more efficient system - that's due to the speed of sound
so .22 cal version is more efficient than .177 cal - at least as far as energy put in by muzzle energy achieved is concerned - it could be different if you focus on penetration, which jsr has found to be better for .177 cal than .22 (IIRC)
Posted: Sun Oct 28, 2012 4:43 pm
by jackssmirkingrevenge
sharpshooter11000 wrote:I'm guessing the metal parts are epoxied in and you didn't machine threads in the CF?
Yup, epoxy to epoxy, dust to dust
there won't be any performace increase to be honest
heavier ammo equalls more efficient system - that's due to the speed of sound
Yup, for a given system, bigger bore and heavier projectile will give more muzzle energy.
so .22 cal version is more efficient than .177 cal - at least as far as energy put in by muzzle energy achieved is concerned - it could be different if you focus on penetration, which jsr has found to be better for .177 cal than .22 (IIRC)
Time for one of my favourite quotes te be dug up
A 68 pounder smoothbore and a 7 inch Armstrong gun firing 200 lb shot had been fired at 4.5 inch plate backed by 18 inches of teak. The 68 pounders had penetrated the target, while the 200 pounder had made hardly any impression on it. Noble showed that the answer lay in the relative velocity of the two projectiles. The 68 pounder had been moving at 1,425 feet per second when it struck, while the 200 pounder was loafing along at a mere 780 feet per second. On the face of it, the 200 pounder with 156,000 foot-pounds of energy should have out performed the 68 pounder with 96,900, but the low velocity of the heavier projectile allowed the plate to deform and resist the blow, whereas the higher velocity of the 68 lb shot tore through the plate before it could begin to absorb the blow.
As Noble said in his paper, "What is wanted is velocity; if you sacrifice it to weight you will only be able to keep knocking at the door without entering."
Posted: Sun Oct 28, 2012 5:22 pm
by sagthegreat
how many psi can this tubing handle?
Posted: Sun Oct 28, 2012 11:08 pm
by jackssmirkingrevenge
sagthegreat wrote:how many psi can this tubing handle?
It's not pressure rated, but given the 1:10 ratio of wall thickness to inner diameter, and small bore, I'm happy to take it to "normal" 300-400 psi pengun pressures.
Posted: Sat Nov 10, 2012 8:29 pm
by Gun Freak
You make me want to give up, Jack. Carbon Fiber makes everything look cooler, I guess
Posted: Sat Nov 10, 2012 8:54 pm
by sagthegreat
What is the highest psi/ smallest wall thickness steel we can get, lets make some pen guns that look like pens and go to 1000 psi, and sell them to the military
Posted: Sun Nov 11, 2012 12:48 am
by jackssmirkingrevenge
Gun Freak wrote:You make me want to give up, Jack.
You misunderstood, I make you want to invest in machine tools
lets make some pen guns that look like pens and go to 1000 psi, and sell them to the military
The military have no use for pen guns, and if they did, they would probably use powder burning ones...
Posted: Sun Nov 11, 2012 2:16 am
by jakethebeast
How about upping pen gun with steroids and then put it to a cane?
Shouldn't be too hard...
Posted: Sun Nov 11, 2012 3:13 am
by jackssmirkingrevenge
jakethebeast wrote:How about upping pen gun with steroids and then put it to a cane?
Shouldn't be too hard...
A cane gun would definitely have much more power due to the bigger volume and barrel length.
http://www.ebay.com/itm/Derby-Handle-Ad ... 3cc7dc0c7c
Pretty cheap if one wanted to convert it...
Posted: Sun Nov 11, 2012 10:31 am
by sagthegreat
lets make some pen guns that look like pens and go to 1000 psi, and sell them to the military
The military have no use for pen guns, and if they did, they would probably use powder burning ones...[/quote]
Spys would have a use, and not to mention the types of substance that can be put on hollow tip pellets to make them "magical"
Posted: Sun Nov 11, 2012 11:45 am
by jackssmirkingrevenge
sagthegreat wrote:Spys would have a use, and not to mention the types of substance that can be put on hollow tip pellets to make them "magical"
If you have magical substances then you don't need much power
if they do need power, powder burners offer it in a much more compact package:
A pneumatic pen gun with the equivalent power to a 22 rimfire would have to be pretty huge.
Posted: Sun Nov 11, 2012 6:39 pm
by sagthegreat
I want that firing cap thing up have. But I don't have a lathe...
Posted: Mon Nov 12, 2012 3:33 am
by jackssmirkingrevenge
sagthegreat wrote:I want that firing cap thing up have. But I don't have a lathe...
You can make a request
here I'm sure someone nice can make you something for a few bucks.