18 replies to this topic

[boltsniper]

There hasn`t been much activity on this board lately either. Whats up? Everybody busy building stuff? Oh well. I`ve been working on 2 guns actually. I had talked about bulding a combustion powered bullpup rifle. I`ve split that one project into two. The rifle I jsut finished is a combsution powered rifle.

Pics here:
http://filebox.vt.ed.....bust1 001.jpg
http://filebox.vt.ed.....bust1 002.jpg

This gun is more of a technology demonstrator than a pratical rifle. Its about 5 feet long. And its pretty heavy. And its bulky. And its kinda frail. And.....you get the picture.

The technical stuff:
The propellant is 50/50 WD-40 and hairspray. That seems to be the most reliable for combustion. The large tank on the bottom is the fuel tank. Fuel is sprayed in through the ball valve and then the valve is shut. The tank is then pressurized with the pump on top. This pressurizing acts to do 2 benficial things: 1)Allows for 4-5 shots before requiring a repump or refuel and 2) greatly increases the O2 in the fuel-air mixture. Once pressurized the trigger on the grip is pressed and a small amount of propellant is released into the combustion chamber (the tank right above the fuel tank). A shell is then loaded into the breach and the rifle is ready to fire. Simply click the aim-n-flmae and you launch a dart about 200 feet. To prep the next shot the shell is removed, the fuel trigger is depressed, and a new shell is loaded. Thats it. The ROF is decently high for a combustion weapon. But the gun is still combersome and a pain. There is still an issue of reliability with the fuel igniting on command. If it fails to ignite usually if you spray a little more into the chamber it works. The breach is a very simple design. To load a shell you pull the barrel forward and insert a shell. Rubber bands hold the shell sandwiched between 2 O-rings. Pretty much the same sealing as in the bolt rifle.

Testing the rifle:
The rifle will consistently shoot a dart 150 feet. With a good tight dart and the correct fuel/air mixture it will shoot about 200 feet. Good figures, but the CO2 rifle will shoot about 150 feet and it is MUCH easier to use and aim.

It was fun building this gun and it works well. But I don`t think I would ever want to use it in any kind of battle



Semi-automatic Bullpup Rifle:
I am still making the bullpup rifle. It has been commited to CO2. I am very pleased with the performance of CO2 and now that I can get upwards of 20 shots per cylinder I beleive it is worth it. This rifle will be true semi-auto. Using a sprung bolt and the addition of a simple piston valve it should work quite well and efficiently. I haven`t thrown together a drawing of the semi-auto action yet but I`ll try soon. The gun will be about 30 inches long and use the same shells as my other rifles. The magazine will be a sprung bottom feed magazine of about 6-7 rounds. As in a bullpup setup the mag will sit directly behind the handle in the stock. The shells will eject out the right side of the stock via a dynamic shell ejector. I`ll post more on this gun when I make some siginificant progress on its construction. Right now I am jsut cutting pieces.

[cxwq]

Once again, awesome work. Glad to see you returning to CO2 from the land of combustion. Having worked quite a bit with combustion spud guns, I saw the reliability issues coming.

I'm curious to find out how many shots per cylinder you get when you go from bolt action to semi-auto. Keep us posted!

[boltsniper]

Yeah, I`m expecting a slight decrease in S/C but I don`t think it will be too bad. The shot of gas will be the same, so I expect the range will probably be more affected than the S/C

[Wax]

Wow, this is really impressive. I was just thinking about the whole issue of people being anti-C02 and all that. I personally wouldn't use C02 and other propellents because the priming part is key to what Nerf is to me, but I don't think that it's a bad thing that Nerf is expanding. It may bring more people into Nerf, just cause it eliminates priming. Also the fact that these things can be semi auto and fire over 100 ft. may bring in some nonbelievers. Clans could ban C02 powered guns from their wars, but people could make their own clan in addition to the air and spring power based clan.

Plus, some of these new developments can be converted to use air power.

[That Bald Guy]

I love the proof-of-concept. I wouldn't mind lugging something like that around, actually. But I have no sense of proportion; something like that could bother someone who just wants a nice little pistol they can mod (nothing wrong with that, either).

[boltsniper]

Thats not the bullpup. I don`t have pictures of that yet. And yes, it is small.....about 2.5 feet overall. The combusto-cannon is now painted flat black and has lost that grip on the bottom so you handle it more like a shotgun now. Suprisingly the darts show no signs of having been in an explosion. They aren`t even warm afterwards.

[SniperWolf]

Just be careful with that combustion rifle BoltSniper...


...The only problem with that is that there is no way to get the same amount of fuel in every time... If you spray just a little too much, that puny tank WILL explode and leave you either dead or with a piece of flaming plastic in your eye. As for the Co2...

go for it!

[cxwq]

5 in a row, you were on a roll.

[Langley]

Damn. I was just working out a way to have a sort of semi auto nerf gun based on a piston valve, and you have to go and work out a c02 fully semi-auto system using it. You're stealing my thunder, man.

[Talio]

Anyone else worry that it's been a quite a while since bolt loser has posted. Lets hope he is still alive.

[Zero Talent]

Damn. I was just working out a way to have a sort of semi auto nerf gun based on a piston valve, and you have to go and work out a c02 fully semi-auto system using it. You're stealing my thunder, man.

He stole your thunder before you knew it existed, Langley. The challenge now lies in making a semi-automatic CO2 homemade that Spoon Six-shooter (I defy you to find Bob as a common or unknown name!) can build. Or a fully-automatic clip-fed blaster. Or even better, a variable semi-automatic/automatic blaster the size and shape of a Colt 1911a1 pistol, with air-actuated kickback recreation. Not to be specific or anything.

[Langley]

um.........How about a footceptor?

Really, though, I think with a couple little tweaks, the clip loaded automatic may be doable. But it would be like theres ten spaces on the clip, each with a seperate valve. But let me get the basic system working first....

[taita cakes]

well links are down...
i tried again today and there still down...
sounds nice tho...
im not one to use CO2....
in fact im not one to build...
im a cheap asswhore.....


but i might be working on a couple of nerf grenades with film canisters soon, mainly because i dont like the idea of trowing a grenade and having to pull a string for it to detonate. and also my dad is an artist who works from photos so i have a lot of film canisters....

[random]

picks are down but if its a clip and it needs to be cocked to load a dart each time you should use a aka cocking design

[Captain]

picks are down but if its a clip and it needs to be cocked to load a dart each time you should use a aka cocking design

The pictures are down because this thread hasn't been posted in for 6 years. Check the dates next time.

EDIT: Understood, Talio.

Edited by Captain, 09 June 2009 - 05:08 PM.

[Talio]

Captian - Don't back seat moderate.

Random - I'm getting sick of this so I'm making an example of you. You're gone for 6 months.

To everyone else - I'm tired of this shit. I'm leaving this open. Next person to post in here gets 6 months himself. I'm not fucking around.