Rifled Barrels
#1
Posted 09 August 2006 - 02:35 PM
#2
Posted 09 August 2006 - 02:49 PM
-GeneralPrimeevil
#3
Posted 09 August 2006 - 03:35 PM
Would still be cool to do though
#5
Posted 09 August 2006 - 05:57 PM
1. The projectile isn't really travelling very quickly and hopefully isn't interacting with the barrel very much
2. The rifling angle would need to be shallower than what's available using standard taps
You wouldn't want to rifle anymore than the the final outer third of the barrel because you need a seal in order for the dart to get up to speed before leaving the barrel. With a lead bullet there are much higher pressures involved that deform the slug into the rifling and thus maintaining the seal. With a foam dart however it's not conforming to the inside of the barrel much at all and any sections with rifling will not maintain a seal because the propelling air will escape through the rifling.
Hard to implement and the gains probably wouldn't be very noticable. The most novel approach to dart spin stabilization that's been discussed here was to simply make a spinning barrel to fire the dart from.
#6
Posted 09 August 2006 - 06:05 PM
#7
Posted 09 August 2006 - 07:31 PM
-sponge
#8
Posted 09 August 2006 - 09:23 PM
#9
Posted 10 August 2006 - 12:10 AM
#10
Posted 10 August 2006 - 09:07 AM
-sponge
Edited by Sponge_Nerfer, 10 August 2006 - 09:16 AM.
#11
Posted 10 August 2006 - 09:53 AM
#12
Posted 10 August 2006 - 10:23 AM
thanks! This might be the advent of field artillery as we know it in nerf!
Rifling will have very little effect on your dart! And even if it DOES have some minor tangible effect, it won't have been worth all the time and effort. Listen to us: we know what we're talking about (Most of the time, anyway).
The way a bullet is affected by rifling is that when the gunpowder goes off, it pushes the bullet down the barrel. The heat and the pressure of the explosion actually deform the bullet. The bullet 'squishes' into the grooves in the barrel. The bullet will now spin, since it is traveling along inside those goorves, and the grooves are in a spiral pattern.
In Nerf, we don't have high enough pressures to actually deform the foam into the grooves of the barrel. The only thing we could do to really get a spin of the dart is to have a barrel with strips of different materials with different frictional properties. Say, copper and brass. We'd have to take two pipes of the same diameter, inner and outer (Which, funnily enough, they don't seem to make), cut them into identical spiraling thirds, and transplant some copper where the brass should be, to give the barrel two distinct surfaces. The two-different-surfaces-method is the only way that I think we could really get a good spin on the dart.
Also, even if we could get this to work effectivley, it wouldn't make that much of a difference. Darts, unlike bullets, are fairly stable in flight. The need no more stability than they have. The reason that grooved barrels work for spud-guns is that potatoes, much like bullets, are very unstable in flight. Also, Spud-guns work with enough pressure to actually deform the potatoe, much like real firearms.
So, if you want to have a 'grenade launcher' type thing, you're best off with a simple home-made plunger setup. Maybe even just a pull-and-release ball-gun.
As to your quote.
thanks! This might be the advent of field artillery as we know it in nerf!
Maybe large diameter FBR will be the catalyst for revolutioanry large-dore Nerf weapons, but rifled barrels will probably play a very small role in that revoluton, if any role at all.
I would love to see some larger big-bore cannons in Nerf. It'd have a very interesting effect on tactics. However, I don't think we'll be seeing people firing Nerf mortars at each other in some public park anytime soon.
Sincereley,
Pat
#13
Posted 10 August 2006 - 10:47 AM
-sponge
#14
Posted 10 August 2006 - 04:37 PM
You could listen to these guys or not.
It's YOUR choice so if you want to try it, go for it.
If you don't try anything you will never know if it helps or hurts.
My imput is rifling is only good if the dart can go 100+ flat because less than that, it won't help very much.
It doesn't bother me at all if people say I'm wrong so cry me a river for all I care.
If you think it will help then go for it and tell us the results.
#15
Posted 10 August 2006 - 10:31 PM
In order for the dart to maintain velocity after traveling down the barrel, it would have to have a tremendous starting force. The only conceivable place I could see the need(?) for rifling would be with a Titan. It would provide enough energy to keep the dart traveling a fair ways after leaving the barrel.
It's a very cool idea; don't get me wrong. But I don't see all that much promise for it. If, however, you do prove me wrong, I offer my sincerest apologies.
~Rings
"I bluff it. I don't throw my weight around and say I know what I'm doing." ~ Mick Jagger
#16
Posted 14 August 2006 - 06:42 AM
rifling is normally added with a gun tap, but the problems involved in doing so with a foam projectile are two fold.
1. The projectile isn't really travelling very quickly and hopefully isn't interacting with the barrel very much
2. The rifling angle would need to be shallower than what's available using standard taps
You wouldn't want to rifle anymore than the the final outer third of the barrel because you need a seal in order for the dart to get up to speed before leaving the barrel. With a lead bullet there are much higher pressures involved that deform the slug into the rifling and thus maintaining the seal. With a foam dart however it's not conforming to the inside of the barrel much at all and any sections with rifling will not maintain a seal because the propelling air will escape through the rifling.
Hard to implement and the gains probably wouldn't be very noticable. The most novel approach to dart spin stabilization that's been discussed here was to simply make a spinning barrel to fire the dart from.
Yeah, he and I were discussing this over AIM. I'm developing a spinning barrel system called the "Inertia Drive", which will hopefully be a completed prototype pretty soon.
I will make the darts with heads made from rubber balls of a very slightly smaller diameter than the dart's body, spreading the weight out over a wider area so it holds its inertia more efficiently. I don't know if anyone has done it before, but I'm doing it now. I'll make a topic about it later.
Anyway, even if rifling would be practical in any way, it would be way too damn hard to implement. The PTEG rifling I've seen is pretty.. messy, to say the least.
-Anubis
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