21 replies to this topic

[laxtk88]

First off, I would like to thank VACC and the other admins for the validation. I’ve waited a few months and appreciate it. Anyways, i would like to know if anyone has tried barrel rifling* or if it is even possible.

*(the helix on the inside of the barrel as seen in the James Bond movie intro)

[bobafan]

No. It isn't really necessary because of the short ranges of our guns and it would let air past the dart.
It would be pretty hard to make the presise grooves that are needed, but if you would like to try it, be our guest.

Welcome to nerfhaven.

[VACC]

Don't thank those assholes, they didn't validate shit....I mean, they've validated hundreds of members while I did nothing but mock them for years, but this week was all Vacc god-damn-it!

Barrel rifling is an interesting concept (I recall a few conversations about it as far back as the list-serve), but I just don't think it's a practical concept for nerf darts. On the other hand, if you have an idea of how to pull it off, running some comaprison tests couldn't hurt..

[laxtk88]

Thank you for your input VACC and Boba and i think I will give it a shot.

Edit- thanks for the welcome

Edited by laxtk88, 31 January 2008 - 04:19 PM.

[Green Riptide]

my NF sort of has rifling just from sanding out the CPC barrel so my darts would fit, but I doubt it does anything.

For rifling to work the ammunition would need to expand and be pressed into the rifling grooves, which frankly I don't see stefans doing. Sure, you could find expanding foam to stuff in the barrel so that this worked, but your gun probably wouldn't have enough power to get the dart out of the barrel. If it were going to work, I'd say it would need to be on a Titan or Big Blast or somesuch.

[Carbon]

This subject has been discussed at length, and previous conclusions have been that it's not necessary. Rifling benefits lead projectiles because they have a tendency to tumble in the air. The gyroscopic effect helps with stability. However, darts are weighted at one end, and the lighter foam helps act as a tail to keep it stable in flight. Also, spinning can can an unpredictatable effect due to off-center weights.

But hey, experiments are good. Search the forums, find out what's been done, and play with the idea.

[frost vectron]

You may want to try searching the forums in the future before posting threads.

http://nerfhaven.com...8242&hl=rifling

By the way, welcome to the 'Haven.

EDIT: Carbon beat me to the punch.

Edited by frost vectron, 31 January 2008 - 04:30 PM.

[laxtk88]

Thanks all for your contributions. I will try this out this weekend with some brass.

PS: Frost, I did use the search button but wanted to see if anyone had tried it after the most recent topic. Also, most of the topics were speculation that was shot down.

Edited by laxtk88, 31 January 2008 - 05:37 PM.

[imaseoulman]

The purpose of rifling a barrel is to increase accuracy. When an object is spinning it requires more force to move that object from it's trajectory (a good example is a bike tire...try balancing on a stationary bicycle...try balancing on a moving bicycle...because the tires are spinning it's more difficult to tip the tires...same thing with turning, if you slow down it's easier to turn). Now, back to NERF and foam darts. It shouldn't be too difficult to get your darts to fly straight. If your darts are fishtailing you probably need a longer barrel and possibly a looser fit (either cook your stefans longer or get wider barrel material). Also, in order to get rifling to work an extreme amount of friction must be placed on the dart (so that it can grip the grooves and begin to spiral)...so much friction that it would likely shred the dart.

On the other hand I have played with the idea of attaching my barrels to a gun inside of ball-bearing housing so that I could attach a rip cord and spin the barrel (similar to a top) and see if it flies any straighter. I don't see that being practical in a war...and again...I've never not been able to get my darts to fly straight with the right length barrel and sufficiently heavy weight (as Carbon mentioned).

If you could, however, successfully rifle a barrel then you may be able to get away with a smaller weight and maintain stability and possibly increase range. I still maintain, however, that rifling a barrel will not help a foam dart's accuracy or stability...but if you really want to, try that ball bearing idea (to make it more practical you could spin it with an electric motor instead of a rip cord).

[Squishy]

You also need to consider that the majority of the weight is in the front of the dart, and the tail end functions as a stabilizer. Rifling for darts will likely decrease range significantly, as the darts are too soft to accept grooves without plenty of compression, they are simply too soft. In addition, any grooves will subtract from the total amount of force moving the dart forward, as some of the force is directed into torquing the dart.

[Kid Flash]

This subject has been discussed at length, and previous conclusions have been that it's not necessary. Rifling benefits lead projectiles because they have a tendency to tumble in the air. The gyroscopic effect helps with stability. However, darts are weighted at one end, and the lighter foam helps act as a tail to keep it stable in flight. Also, spinning can can an unpredictatable effect due to off-center weights.

But hey, experiments are good. Search the forums, find out what's been done, and play with the idea.

You also need to consider that the majority of the weight is in the front of the dart, and the tail end functions as a stabilizer. Rifling for darts will likely decrease range significantly, as the darts are too soft to accept grooves without plenty of compression, they are simply too soft. In addition, any grooves will subtract from the total amount of force moving the dart forward, as some of the force is directed into torquing the dart.

look at that... those posts arent much different. not much is being done here except repeating what people already said.

[Peter]

We need to stop comparing nerf ballistics to those of rifled guns.



Rifling, in the form being discussed, would probably add more harm than anything positive. Since with nerf guns we have a lot less force to work with, we can't much of it to provide the spinning without seriously compromising the range for a nominal increase in accuracy. Since friction is independent of surface area the only feasible option that comes to mind is one that does not involve the foam being pressed against anything, but rather the tip of the dart. CaptainSlug's foam tips come to mind, because they are perfectly circular (for our purposes at least) and can probably be worked in quite well with whatever sort of 'rifling' system that could be made.

What I am saying at this point is this:


---------------------
========|
---------------------

Where the | is the tip of the dart (circular tip) that is pressed against the barrel, and then would be accepted into any grooves or rifling implementation.

In practice, this provides much more consistency (assuming that your circular tips are all the same [i.e. Slug's]) in terms of contact with the rifling in comparison to a foam dart (width, type, and batch inconsistencies)




However, the next problem is actually making a barrel that would work well enough. I think it would be better to use barrel material like the aluminum tubing (Part# 1658T49) that Slug found from McMaster (I <3 McMaster btw) due to its lower coefficient of friction, however another cheaper material such as PVC could be used first to test methods, but the aluminum is dreadfully cheap as it is. If using a PVC type i'd probably recommend trying several test groups with variations on each (maybe some with dry lubricant like graphite). I'm not too knowledgeable on any methods of adding grooves(lathe maybe?). You'd have to ask someone like CaptainSlug.



Another idea that occurred to me is that instead of rifling the entire barrel, you could rifle it at the very end, or at the beginning, again you'd have to perform tests as those are the only thing that can really tell us what's the best.



All in all, good luck.

[Famine]

LAX; I'm going to go out on a limb here and guess that you're trying to find a way to make a homemade gun (built by a clanmate of yours) fire more accurately.

Now that you have access to the draconian well of knowledge we call NerfHaven, why not try posing your question in a different form?

IE - I have a homemade Nerf gun that takes entirely too long to prime and therefore need it to be as accurate as possible. What type/length of barrel do you recommend and what type of darts should I put in it (Stefan, CDTD, Zeros, Webby, etc)?

[Squishy]

look at that... those posts arent much different. not much is being done here except repeating what people already said.

Don't be an asshat. Though I did repeat that the center of balance helps to correct unstable flights, I see no other faults. It doesn't appear as though your comments are adding any substance themselves.

[nerfnerd88]

Just do this. Hold a stock dart in your hand. Now just gently flick or toss it. It should fly around 25ft. Now try to throw it like a football. There's your answer.

[bpso86]

I've always wondered about this as well, but more for the application of firing streamline darts from high powered guns. I think it could help them a lot, but I'm questioning the durability... It's definitely something that I won't be trying, but it is interesting to think about.

[Ubermensch]

Not sure if someone posted this, but...

http://nerfhq.com/nerfworld/

Look at the rifled PETG in the homemades section.

[Squishy]

That's interesting: instead of taking and making rifling effect the dart and directly giving torque to that, it puts a 'spin' on the airflow. Nice find!

[frost vectron]

Thanks all for your contributions. I will try this out this weekend with some brass.

PS: Frost, I did use the search button but wanted to see if anyone had tried it after the most recent topic. Also, most of the topics were speculation that was shot down.

I was under the impression that rifling barrels do not work in the nerf world and so the idea of it was shot down. The fact that nobody has actually brought forth a working prototype only serves to strengthen this conclusion.

[Ubermensch]

'scuse me, Frost, but I believe the rifled PETG did increase ranges, but made the gun more inconsistent. Thus, it was a technical success.

[laxtk88]

Thanks all. Famine: i am not making a homemade but simply curious as to the rifiling of barrels in the nerf world. Ubermensch: thanks for the link i will most definatly try the riflid PETG.