15 replies to this topic

[King Of Butt Land]

I was just browsing some old homemade topics about bullpups and rotary breaches when I realized that you could have a magazine with the darts sitting horizontaly to the gun. It would be spring fed and drop into a rotary breach in the same oriention of the breach. The breach would only be in the same orientaion as the darts when the gun was being cocked so when you pulled back the bolt or charging handle the breach would rotate, a dart would fall in, then as the handle or bolt was being brought back forward it rotate back into orientation with the barrel. I may try fabricating a design such as this in a future project. This would allow for huge advangtages in ammo capacity and rate of fire. Let me know what you think of my plans. If you want to contact about anything else Instant message me on Ramones994.

-Butt

[ompa]

There was a discussion about this very same topic some time ago, although I'm not sure which forums they were on. May have been Boltsniper's. Anyways, the problem that came up I believe was how to seal the dart after rotation. If you plan to use a bolt that covers or pushes forwards the dart, you're going to have to have something that turns AND pushes the bolt consecutively in one smooth action. That will probably be a bitch to get the timing down right, but it shouldn't be impossible. If you get stuck or anything though, do post your progress and I'm sure at least one of the members would be able to help.

~ompa

[King Of Butt Land]

I was thinking that you could have a peice of brass pushing the dart into the barrel as the breach rotated back into postition.

-Butt

Edit: oops i realized thats what you were saying. I was thinking if i could properly time rack and pinion or a pulleys could be effective.

Edited by King Of Butt Land, 21 August 2006 - 11:28 AM.

[ompa]

Yeah exactly; I'm just saying it's going to be hard to get the timing down. It's definately do-able, but it's going to be like getting a Nf-plunger to fire at the correct time when put into a Mav.

~ompa

[Carbon]

Yeah, that discussion was over at Boltsniper.com. Anyway, Getting a system which could advance and rotate at the same time would require some mechanicals, but it's definitely doable. Another way to approach it that was discussed was to use it as a method to hold multiple small gravity feed magazines, say three shots each. You could set up a turntable with say, 12 mags on it, three shots each. Use up one mag, then rotate the next one in place, using a small detent to make sure it centered up over the breech. It'd definitely work, it'd just be a matter of how large such a setup would be sitting on top of a nerf gun.

Edited by Carbon, 21 August 2006 - 11:30 AM.

[King Of Butt Land]

That is a good idea Carbon but I am aiming at have a compact design which has a large ammo capacity.

-Butt

[Carbon]

That is a good idea Carbon but I am aiming at have a compact design which has a large ammo capacity.

-Butt

Ugh..and I'm realizing that I totally misread yours and ompa's posts...thinking you were talking about rotating the ammo, rather than the breech. That's what I get for reading too fast.

Anyway, yeah...a breech like you're talking about would be great, because a big part of dart jams occur when the breech is halfway open, and a dart goes in crooked, then the breech tries to close over it. I'm guessing you mean a breech where a cylinder revolves inside of a pipe. ...which would be good because the entire length of breech would be open at the same time.

The biggest problem with a breech like this is the seal...the opening in the revolving part would need to seal off against the tube that it's in. The tolerances of a piece like this would be tight. But even if you couldn't get a single motion charge handle (prime and fire) to work, it'd be a great innovation because it'd jam less frequently (It could be a loading motion by moving a lever from side to side.)

Looking forward to seeing your work!

[King Of Butt Land]

What I am aiming at Carbon is to get something that has the same ammo feed system as a P90 (at least i think so). The darts sit horizontal at the top of the weapon and are pushing into a rotating section of pipe with slightly large dimensions of the stefan but it is only a half pipe. Then this is rotated 90 degrees to align with the barrel. Then the the other part of the bolt will push the dart in the barrel create a seal and boom. The first effective bullpup nerf rifle.




Hopefuly that picture helps explain what I plan to do.

-Butt

Edited by King Of Butt Land, 21 August 2006 - 06:51 PM.

[King Of Butt Land]

Sorry about double posting but I feared that if I edited that post yet again you the reader would get overwhelmed by the awesome of my crappy diagrams. Behold.


http://img207.images...="IPB Image" />

-Butt

[Gyrvalcon]

The magazine would be cool and all, but I don't think that's the obstacle that needs to be overcome when making a bullpup design. The pressure chamber is the part that takes up space behind the breech, so it either needs to be relocated, miniaturized, or exchanged for a compressed air and valve system.

Unless you were talking about a compressed air and valve system from the start.

My point is, the type of magazine used doesn't make a weapon a bullpup, it is where the magazine is in relation to the trigger.

[FromAbove]

I'm glad this topic came up because it reminded me to post a pic of my bull-pup nerf gun.
The reaper mk.2

I think the p90 mag would work, but I agree with Carbon about your sealing surfaces because your constraints would probably be too tight to worry about o-rings, so look towards brass.

FA.

[King Of Butt Land]

Yes, brass is what I will use, and I will be a spring powered gun Gyrvalcon.

Edit: The reason I posted the pic of the P90 mag is the rotor thing at the bottom. Notice how the bullet in there has different orientaion than the rest. Thats what I am aiming to do with my design.

-Butt

Edited by King Of Butt Land, 22 August 2006 - 09:11 AM.

[sam]

The first effective bullpup nerf rifle.

I thought the SNAP 4 was pretty effective.

[King Of Butt Land]

I didn't know the snap-4 was bullpup, please explain.

-Butt

[davidbowie]

The SNAP-4 has a magazine on it. That magazine is behind the grip.

Also, The Reaper was a bullpup.

The mechanism you're talking about would be kinda cool, but it's in no way required for a bullpup.

[Carbon]

The SNAP-4 has a magazine on it. That magazine is behind the grip.

To be fair, the SNAP-4 is pretty borderline as a BP, in that the mag is on top of the trigger mechanism. It could still move a few inches back, so it could be a true bullpup, but I made some concessions for cosmetics and simplicity of mechanicals.

Edited by Carbon, 22 August 2006 - 03:52 PM.