18 replies to this topic

[zaphodB]

So, I've been modifying nerf guns for a while, and before that i've done other projects that had to do with pneumatics. When I searched for barrel modifications, it seems like everyone is "nesting" a smaller barrel inside a larger one. When i looked into it futher, i didnt see a reason for doing so, peopls just seemed to do it. So my question is this: why nest barrels? It seems like the gun would be more efficient at exerting all of its force if the dart were snug in the barrel the entire time.

Oh, and i really did reserach this, and i really didn't find any answers.

[Carbon]

You only need to hold the dart snugly until maximum pressure is built behind the dart: after that, the barrel is just friction slowing it down. So, a small section of barrel holds the dart snugly, and the rest of the barrel gives accuracy. This is usually done in springers, as they put out less air that pneumatic guns. Guns with a large air output can make use of a longer snug barrel.

[zaphodB]

so, as a follow up question, would it be possible/feasable to rifle a barrel? That would give a lot more accuracy than a less snug barrel that the dart smacks around on would.

[CD-R]

so, as a follow up question, would it be possible/feasable to rifle a barrel? That would give a lot more accuracy than a less snug barrel that the dart smacks around on would.

That has been extensively discussed (maybe too extensively). The general consensus was that it was not possible. You can use the search function to find the thread.

[butleriscool123]

so, as a follow up question, would it be possible/feasable to rifle a barrel? That would give a lot more accuracy than a less snug barrel that the dart smacks around on would.

There was a topic on that, no it wouldn't.
Edit: Dang CD-R beat me to it.

Edited by butleriscool123, 28 May 2007 - 09:55 PM.

[zaphodB]

it seems to me that all the rifling that was attempted was rifling the dart itself, with a hot glue gun. what I'm talking about is rifling the barrel, with a dril or some other thing. I feel like people who've done rifling before have done it quickly as a sort of "hey, rifling the barrel might work, they do it in real guns" and then quickly trying to do it with a dremel or something. In order to do what I'm talking about, the rifling would have to be etched in with a blade of some sort (like a nail, or a razor) in a method similar to how rifling was done when it was first introduced (about the civil war period). Also, people who have done it before have probably put too many rotations in the rifling. A half turn or 3/4 turn would be enough to create gyroscopic stability. Anyways, it would be difficult to do, but interesting to see how it works. I may end up doing it to a barrel for my titan, and I'll let you guys know how it worked out if i did it.

[Carbon]

It's been discussed both ways.

It's because of the inherent difference between the different kinds of ammo. A firearm slug has the tendancy to tumble when fired, since it doesn't have a weighted front. Also, the pressures involved are able to physically force the slug into grooves, causing the spin.

Nerf, on the other hand, gets no gain from a spin, because the ammo is weighted at the tip. Also, pressures are too low to make use of the rifling.

Search out the other thread and read through it (As CD-R said, it was discussed at length). There's really no benefits to be had in doing it, due to differences between firearm and nerf ammo.

[CD-R]

I was to lazy to make a write up on my "rifling method", but it did get the darts spinning due to spiraling grooves on the inside of the barrel. Unfortunately, there is no advantage to this, as it purely served to make my darts curve off in all strange directions. Basically, don't waste your time with it. There are many things you can work on that will improve your guns much more, and with much less work involved.

[Dart Attack]

so, as a follow up question, would it be possible/feasable to rifle a barrel? That would give a lot more accuracy than a less snug barrel that the dart smacks around on would.

There was a topic on that, no it wouldn't.
Edit: Dang CD-R beat me to it.

Here is a link if you want to read about it.
http://nerfhaven.com...=rifled barrels

[zaphodB]

As i said before "people who have done it before have probably put too many rotations in the rifling. A half turn or 3/4 turn would be enough to create gyroscopic stability." the thread you sent used a rod with at least four revolutions per inch. with that many, it's almost the same thing as making grooves at right angles to the barrel , which is why it didn't work. I'm talking about threading it so that there's about one full rotation ever two feet. As far as the difference in ammunition goes, the rifling would allow for very short stefens that maintain or surpass the accuracy of normal stefens. If you don't understand exactly how rifling works, and how it should be used effectively, then any attempt at rifling would fail.

[rebsol]

[quote name='zaphodB' date='May 28 2007, 10:10 PM' post='108067']
rifling was done when it was first introduced (about the civil war period).
I'm a history stickler, and if you ever read 1776 by David mcconna- something you will know that rifling was introduced by Virginia marksmen that aided the continental army at the siege of Boston. Just telling you.

[zaphodB]

Actually, i think i meant american revolution. Minor brain fart. anyway, by point is they used a complex wooden setup to rifle their barrels, and since they did it back then, it shouldn't be too hard to do it now.

[Carbon]

This has already been discussed. Repeatedly. And the summary has always been the same.

If you think it can be done, you should do it and post the results; this discussion has been had before.

[Ronster]

This topic has reminded me of a question I've long had...
Let's say I've got a homemade gun that uses shells.
I've used both CPVC on my barrel and the shells.
I've lathed down the barrel to fit as snug as brass, but I can't lathe the shell down on the inside to match the barrel due to the fact that I've already lathed the outside to fit in the bolt.
Would that make much of a change in the ranges for the shell and the barrel to have different IDs?

Edited by Ronster, 29 May 2007 - 06:46 PM.

[zaphodB]

Is the inside of the shell narrower or wider than the barrel? Actually, either way it will effect the range negatively. I get the feeling that the inside of the shell is wider than the barrel and if that's true, the dart may get caught a bit on the lip that forms where the shell meets the barrel.

[Ronster]

Narrower.

[zaphodB]

the shell is narrower than the barrel? well, you're going to lose some air pressure, but if the barrel is snug normally, you should be fine. I wouldn't store the darts inside the shells though, because then they won't fit well in any of your other guns.

[PointBlank]

So, I've been modifying nerf guns for a while, and before that i've done other projects that had to do with pneumatics. When I searched for barrel modifications, it seems like everyone is "nesting" a smaller barrel inside a larger one. When i looked into it futher, i didnt see a reason for doing so, peopls just seemed to do it. So my question is this: why nest barrels? It seems like the gun would be more efficient at exerting all of its force if the dart were snug in the barrel the entire time.

Oh, and i really did reserach this, and i really didn't find any answers.

Yah, I nest my barrels to make them more stable.

[firstblood]

Yah, I nest my barrels to make them more stable.
[/quote]


Thats what I thought too.