Stabilizing Paintballs-rifling


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zahc
October 17, 2003, 08:23 PM
Ok, I've given up on asking this on PB boards, because everyone seems to be 13 years old with opinions gallore. So I'm fishing for people more informed on ballistic-type issues.

I play paintball. Paintballs are crono'd under 300FPS for comfort. This makes for a short range. Nature of the game; I can deal. But what i can't deal with is the disgusting accuracy I see from most markers. Some consider a 2 foot group at 30 yards good accuracy. I am disgusted.

Paintball markers have smoothbore barrels. Only a very few rifles barrels have been made. My question is, why they are not overwhelmingly popular. Why do they not increase paint ball accuracy? If they did, they would be the standard (I would think).

I don't see why a nicely polygonally rifled barrel wouldn't work with paintballs. But they must not. So any ideas why?

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Penforhire
October 17, 2003, 09:28 PM
Paintballs have to be relatively fragile to pop open if your muzzle velocity is only 300 fps (max, 285 is a more common field limit and that's peak, not average) at .68 diameter and you want to mark someone 30+ feet away. Rifling tends to weaken the ball and you got more bursts in the barrel. And we all know sploogies suck...

Second, the balls are spherical and imparting a spin doesn't stabilize a smooth sphere. You can get more loft with backspin (e.g. Tippy's bent barrel design) but then you fight curve-balls constantly and even today's best balls are not shaped repeatably enough (think about what you can do with a ping pong ball and a grippy paddle). Consider that even a perfect sphere paintball has a diameter that varies with humidity and temperature (ergo, the growth in the sized barrel market... I love my CP Products bores) so the seal to the barrel varies.

Experiments, over a decade ago, in redesigning paintball shapes for better stability led to too much penetration power at the receiving end. They became dangerous projectiles.

This is not to say it will never be possible. Just that the materials technology is not yet there. Remember also that we get economy from current ball designs because they use relatively simple vitamin pill encapsulating machines to fill & form the skins.

PerfectGlock
October 18, 2003, 01:35 PM
Check out www.hammerheadpaintball.com , they make rifled paintball barrels. APG had nice things to say, and so do those at www.pbreview.com .

I think the reason why they don't work like they are intended to are because of the same reason why a raw egg won't spin. Paintballs are like waterballoons, not solid projectiles. The best thing to do is to get a good paint-to-barrel match.

zahc
October 18, 2003, 05:50 PM
I think the reason why they don't work like they are intended to are because of the same reason why a raw egg won't spin. Paintballs are like waterballoons, not solid projectiles. \

...but the flatline spins them



Second, the balls are spherical and imparting a spin doesn't stabilize a smooth sphere.

...but rifles stabilize lead roundballs way better than smoothbores do.

rayra
October 18, 2003, 06:55 PM
5-6yrs ago there was a lot of press about the 'starfire' (name?) bolt, usually sold for or used in tippman markers. supposedly 'swirling' the air pulse to impart spin on the paintball. I tried one, no significant difference.

Also read about folks using an automotive flexible brake-cylinger hone to polish their bores, and the theory that super-smooth would NOT impart any spin on the ball, preventing to from hooking or slicing off-axis.
I lapped mine with valve-lapping compound and metal polishing paste until it was mirror shiny. Again little difference.

Got tired of playing with wipers, and had ZERO interest in buying paintgun markers that cost more than real guns, gave it up.

http://home.earthlink.net/~rayra/mar/pb-mymask.jpg http://home.earthlink.net/~rayra/mar/pb-mypro.jpg
http://home.earthlink.net/~rayra/mar/waiting.jpg

JimJD
October 18, 2003, 09:16 PM
Not only does it have something to do with the projectile shape, but it is also dependent on what type of air system you are using.

Is it CO2, or HPA? Do you have a good regulator/valve? Etc, Etc.
Plus, there's a liquid fill in the PB, that does'nt help.
Add to that, PB's have many Q.C. problems, you get dimples, weak shells, etc. It's not up to the snuff that bullets are.
PB's are just inherently innaccurate. For now.

Tippmann's flatline is the only real advance in this type of technology. But even that system has problems and limitations. Distance is great, Accuracy is still so-so.
As stated before, a good paint to barrel size match is the only way to go for now.
Hopefully that will change with time.

Penforhire
October 19, 2003, 12:17 AM
Like I mentioned, the Flatline just imparts lift with backspin. That's not stability and it sure isn't accuracy.

My own experiments proved a smooth bore was an improvement over a coarse finish, but not a huge deal, like Rayra said. Honing was popular even a decade ago. Brass is really easy to mirror finish and seal but anodized aluminum is tough.

Let me ask you a tough but related question. What is the optimum length for a paintball marker barrel in terms of accuracy?

JimJD
October 19, 2003, 01:03 AM
Supposedly, it's something like four to six inches.
Most of the new barrel systems that use inserts like the Phreak, PMI evil pipe, empire, etc. Have ones that are short. Those are the "backs".
That is the only part of the barrel that makes contact with the PB.

The "fronts" of the barrel are supposedly shaped in a manner that stabilizes the air currents that surround the PB.
Which according to the makers, creates a more accurate shot.
Ehhh... I don't know how much I believe it though.
I'd love to see some hardcore scientific data on the subject.

I use a Lapco Bigshot 12 in., and am very happy with it. Great price, great performance.
Too many flatlines have had their rough inner surface go smooth after use.
Tippmann does'nt seem to be standing behind that product too much.
There was a big stink about it on the Tippmann forums a few months ago.
Too bad, because tippmann makes some great stuff for a good price.

C.R.Sam
October 19, 2003, 02:08 AM
At the speeds encountered...
Seems that dimpling, evenly, the projectile would help a little.
The liquid center is going to give fits if spun.

Sam

rayra
October 19, 2003, 03:51 AM
but wouldn't any dimples on the surface of the gel-cap be mirrored on the inner surface, causing the very disturbance of the paint that you mention?

JimJD
October 19, 2003, 02:24 PM
No, the dimpling is never even.
It's always the result of a mistake during fabrication.
Every dimpled PB that was fired from my gun had a horrible flight path.

Once, I took a bag full of dimpled PB's and shot them through my gun, if they did'nt break, they would curve and dip, etc. on the way to the target.
The horror, the horror...:D

rayra
October 19, 2003, 04:31 PM
JimJD, those accidental dimples do indeed disturb the flight of the paintball.
CRSAM & I were talking aobut the kind of deliberate dimpling pattern you see on golf balls. Spinning correctly, they add loft and range to the ball's flight. Launch it wrong, put the wrong spin on the ball, you get a hook or a slice.
and certainly a solid reason why such a thing would work on a pb marker - how do you make the paintball spin the same way every time? And rifling + dimples = paintball veering to whichever direction the rifling twists.

George Hill
October 19, 2003, 04:57 PM
The cats that make the automag make a marker that put a backspin on the ball too. The idea isn't for accuracy, but for a flatter trajectory.
It does work. But it really doesn't make for any increased accuracy at all. Just gives you about 30 yards extra in some cases.

The key to PB Accuracy is the fit of the paint to the bore of the barrel. This is why you see the pro guys with bags of different barrels all in different sizes.

Penforhire
October 19, 2003, 06:36 PM
The comments about a liquid center are dead-on. One materials development I was talking about is to make something like chalk. A solid projectile that will explode and mark on impact. Then you could spin it with no liquid-center issues. And/or it could be finned (vortex style if spun). Unfortunately, at the moment, you'd also kill and maim a bunch more players too... But any of you going into the material sciences might want to keep chewing on this one since something that worked would take the paintball world by storm.

C.R.Sam
October 19, 2003, 08:12 PM
Smooth golfball (yes Virginia, there is such) flys eratically and short.
Properly dimpled and well struck ball flys truer and further.
Airflow around the object. Smooth sphere really sucks drag wise.
Grooving like a croquet ball or dimpling like a golf ball helps.
Grooving no good for projectiles unless properly oriented at firing.

Term dimpling not to be confused with manufacturing blurps as found on present balls. I'm talking precision dimpling.

A paint ball that flys true can be made but tis going to be pricy.

Sam

JimJD
October 19, 2003, 09:01 PM
Oh!
That's what you guys and Gals meant....
I'd love it if the industry could make one like that!
But current fabrication techniques don't allow for it... :(
I have a feeling if they tried with current tech. the PB gun would be a break-o-matic...
Reminds me of which, I really hate it when some guys say they're a "paintball sniper".... Oh COME ON!!!

gun-fucious
October 20, 2003, 08:49 PM
there is an accurate paintball ammo
http://www.quartermasterpolice.com/303_ammo_indelible.jpg
but its a buck a round

Tom Kaye from AGD makes it and the FN303s that shoot it
http://www.quartermasterpolice.com/303_ammo_indelible.jpg

Tom has prolly done more research into paintball physics than most
http://www.automags.org/forums/forumdisplay.php?s=&forumid=6

Tom has also shot dimpled 68 cal ballls:
http://www.automags.org/forums/showthread.php?s=&threadid=59298

Blain
October 20, 2003, 10:34 PM
What is the regular accuracy for paintballs at 50 yards? 75? 100? There must be better accuracy in guns than 2 feet!

gun-fucious
October 20, 2003, 11:35 PM
the slow fire, 3 foot group at 60 feet is why you walk fire onto a target at 10 rounds per second

once you have the target ranged, you can lock down on a window and dump a hopper into a 1 foot square

when dealing with log bunkers, you stitch them back and forth in bursts and sometimes nail the dood through a crack

seldom do you one shot stop in paintball

i do have a red dot sighted in for 40 foot targets and have connected quickly

but if you try to snipe with one shot, you can miss at 20 feet

'tis better to burst 'em

the quality of your ammo is a big factor
so is matching the current size of the paint to the barrel bore
i run a sceptor and have re sleaved 3 times in one day
as the humidity went up, the paint grew from .684 to .688 to .690

whats really funny is to watch the cork screwing and jagging when you have a barrel break.

Penforhire
October 21, 2003, 04:30 PM
I'm with Gun-Fucious here. A 3-round burst sort of is a sniper shot in paintball. That way you have high odds of at least one ball running true to a red dot sight Past about 40-odd feet you're lofting them in there and hoping they hit something hard, like a mask, anyway.

Tom's got some cool stuff but I've never been an automag fan. Too much inertial reaction going on. Give me an electric grip autococker any day...

zahc
October 21, 2003, 09:47 PM
What is the regular accuracy for paintballs at 50 yards? 75? 100? There must be better accuracy in guns than 2 feet!

50 yards is well out of paintball range. Don't even waste paint past thirty. I don't quite get your second sentence. :confused:

gun-fucious
October 22, 2003, 01:05 AM
2 of my team mates run X-mags
but i run a WASed Viking

a Halo becomes empty in under 10 seconds

i was watching a 6 on 2 shoot out from some fairly well protected bunkers

lots of shooting for 5 minutes but no connections
i did the terminator walk in while hosing the 2 bunkers

they assumed the fetal postion
:evil:

zahc
October 23, 2003, 11:32 AM
a Halo becomes empty in under 10 seconds

$40 paint=$.02 a shot=$4.00 for a 200rd hopper.

$4.00 in 10 seconds=$24.00 per minute.:what:

The only bad thing about paintball. When people ask how much I play I always answer "Not nearly as much as I'd like; way more than I can afford".

JimJD
October 23, 2003, 12:18 PM
Paint prices are horrible, are'nt they?
It has made me conserve my shots though.... and that's a good thing.
I always come home with paint, while my friends would have bought at least a case and a half, and no paint to take home.
Great thing is , I would always have the most eliminations at the end of the day.

Penforhire
October 23, 2003, 02:41 PM
Hah! When I started we bought 20 cases of crappy paint at a time and it cost about $0.08 a shot at that. Anyone else remember the revelation of "direct feed" conversions of Sheridan PGP's and auto-trigger linkages added to the pumps? Boy we could throw a lot 'o paint! :)

Yeah right. Now we might as well have a liquid tank and hose down the enemy. The game is more fun with a lower rate of fire. Anyone for a round with ATS sniper rifles or pumps?

JimJD
October 23, 2003, 10:55 PM
Oh, I long for the good 'ol days when pump was king.
Well, not totally... But I feel the same about the "paint hose" problem.

Way too many kids who play today are heavy on that trigger.
It's just wrong to see some fourteen year old kid running down the field with an angel or some other type of "uber-gun".
But it's great to see the look on their face when I eliminate them with my Tippmann!:D

gun-fucious
October 23, 2003, 11:46 PM
i've got a really nice Viper M1 thats pretty accurate,
but after being laned in by "Timmy"
i decided to join the escalation.

i'd love to have a hyper accurate marker that would wack a mole at 60 feet.
i would certainly save on paint

the FN/AGD system seems to be accurate
but thats a buck a ball and not field legal

i've seen
spiral ported barrels
open rail barrels
adjustable bore barrels
3 foot barrels
6 inch barrels
sleaved barrels
titanium barrels
and carbon fiber barrels

the common denominator is a 68 caliber encapsulated glob of paint
and the ballistics of that 300fps ball is just goofy

longballs bounce off 70 foot snipes
unless you buy the more fragile expensive paint
and that can implode in yer barrel if you look at it crosseyed

It seems like most of the development these daze is for X-ball/ Speedball
Where in the backman drops 6, 200 round tubes as fast as possible.

I prefer old skool woodsball and pod tactics.

Its a heck of a nickle pitch

:D

Penforhire
October 24, 2003, 02:54 PM
The electric-triggered sear is the coolest thing I've seen in a long time. I have an amazingly tricked out Black Magic Autococker, cost me more than any of my firearms, but I have as much or more fun with my $300 M3 (aka Black Dragun), a cheap-as-can-be blow-back Spyder design with an electric sear. I wish the ATS design was more competitive when you have to go to "hose mode." That's the marker for guys who like GUNS.

Gun-fucious, you nailed the variety of barrels out there. I love the intimidation factor of long barrels but try anything over 14" in the woods for a while and you get real tired of getting it around obstacles. And fuggettaboutit in speedball...

gun-fucious
October 24, 2003, 11:35 PM
if you think a 16 inch barrel is a pain in the woods

you should try lugging a 5 foot LAWS about

:evil:

or our Ballista:
http://www.darkviking.com/modules.php?name=coppermine&file=displayimagepopup&pid=39&fullsize=1

run away!

goon
November 4, 2003, 06:08 PM
Are there any guns out there that you could actually hit something with?
I don't have one yet, but I would like to get into the sport.
I would like to get one that I could hit a guy with as far away as possible.
Pump or even something slower would be OK if I could hit them twice as far away as they could hit me.
Also, if that animal doesn't exist, what should I start with?
Any suggestions as to what to buy and where I could get it the cheapest would be great.
And how much is it gonna cost me to get started?

And BTW- How come no one has come up with a cartridge firing paintball gun?

Joe Demko
November 4, 2003, 06:20 PM
Cartridge systems have been around. I remembeer one from all the way back in the 80's that looked like a MAC submachinegun. The cartridges used primers as propellant. Yes, it was full-auto too.

gun-fucious
November 4, 2003, 09:18 PM
the limitations are

A] ~300fps ball speed

B] a 68 caliber liquid filled gellatine capsule

it doesn't matter if you pump it or semi auto it

its the irregular ball at 300fps ballistics (or lack there of) that determine what you will hit

its kind of frustrating to not be able to connect at 80 feet
but neither can yer target
if you get to tunneled on one dood
you will get wacked by his teammate


a good starter is the tippmann 98
the only gun that strikes further is the tippmann flatline barrel
it back spins the ball and it flys ~15 feet further
but the air drag has pretty much slowed the ball
down to bounce, not break speed at that distance

if you are getting into paintball to play woodsball/rec ball
then you can have a great game with nearly any marker

X-ball/Speedball is a firefight with 100 balls in the air at any moment

Penforhire
November 5, 2003, 02:30 PM
Goon, ebay is your friend. The Tippy suggestion is a good one. I'd have to add the Spyder clones work good enough too. Make the price stretch to get a compressed air system instead of CO2, although you can switch most markers later. Don't get a pump unless everyone you play with uses 'em. You can snipe with a semi if that's your bag. As an upgrade get a sized barrel set to match your barrel to your paint.

Your paint hopper won't matter for sniping but the electric-stir hoppers are a must for firefights.

Don't save money by using old or cheap paintballs. At the same time, don't start with extremely thin-wall balls designed for tournament use.

Get a mask that is comfortable and protects your ears and throat (or wear a neoprene neckie). A good set of knee and elbow pads made my game better.

You're not going to legally outrange your opponents. Work on flanking moves, teamwork, and proper use of cover.

Cartridges are too expensive and noisy (believe it or not the BATF thinks a paintball silencer is the real deal).

zahc
November 5, 2003, 03:07 PM
Goon-Forget the marker. First buy a good mask. (I like Vforce masks)

Once you have a good mask, tippmann 98; spyder clone.

Think before buying compressed air though, I have to drive 50 miles to get a compressed air fill, but I can fill CO2 in my basement for pennies. I run regulated CO2 in a 20oz tank with an anti siphon and don't do bad at all.

Buy decent paint.

Penforhire
November 5, 2003, 07:00 PM
One note about compressed air. If you or a buddy are dive certified you can get a scuba tank filled (3,000 PSI in an 80 aluminum cylinder is common) at any dive shop for cheap and a $45 adapter can fill your marker bottles for a while.

Curiously, my local field doesn't allow scuba tanks even in their parking lots. Must've had problems on hot days blowing a burst disk. But they do offer air fills and they can top off my 4500 PSI bottle, which I can't do at home.

gun-fucious
November 7, 2003, 01:21 PM
heres one attempt at a sniper rifle:
http://www.thehighroad.org/attachment.php?s=&postid=590284

in conventional firearms a longer barrel means more accuracy (to a point)

in a marker you want ~300 fps at the muzzle

so with a 12 inch barrel, 300 fps takes X amount of gas
whats a 50 inch barreled marker going to need in gas
to overcome 38 more inches of drag?

Prolly 4X the amount of gas

more gas required, fewer shots per tank
and the unstable projectile is still
gonna exit the maw at 300 fps

Penforhire
November 8, 2003, 06:16 PM
What is sad is that a well-made paint-marker silencer, by reducing pressure behind the ball as it exits the barrel, enhances accuracy. Sad because the BATF has thrown fits about them in the past.

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