MilSimEmpire.com Default Font Increase Font Increase Font


All times are UTC - 5 hours  




Post new topic Reply to topic  [ 10 posts ]  Share Topic:
Author Message
 Post subject: Hexagonal Barrel? ? ?
PostPosted: Fri Mar 21, 2008 5:19 pm 
Offline
E-2  PFC

Joined: Sun Feb 10, 2008 5:30 pm
Posts: 25
Location: Central Alabama
I don't know how well this would transfer to paintball but I wonder what you guys think. I know on Glock pistols the inner diameter of the barrel is hexagonal not cylindrical. This results in a tighter bullet/barrel match and higher shot velocities because less gas escapes from around the bullet, has anyone tried this with a paintball barrel and if so what were the results? I think you might get SLIGHTLY more efficient air use and a little better accuracy. Am I right or do I have my physics way off? ? ?

_________________
"There are no dirty tricks, just effective tactics."


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Mar 21, 2008 5:55 pm 
Offline
E-3 Specialists
User avatar

Joined: Mon Jan 28, 2008 4:16 pm
Posts: 68
Location: Salem, WI
The hexagonal barrel of the Glock is actually a result of the hammer forging manufacturing process. They use it reduce production cost and decrease the cleaning requirements of the barrel in comparison to a broached or cut rifle barrel. The chamber pressure of any given firearm will be based mainly on the powder charge in the shell and the weight of the bullet. All manufactures build their guns to meet or exceed SAAMI load data for each caliber. I think the high pressures need to make a paintball conform to a hexagonal barrel, even one with very smooth interior contours, would compromise the shell of the ball. What you would gain in air use efficiency you would loose in broken paint balls. Unlike a firearm which shoots a relatively small and dense object at very high velocities from a chamber and barrel who's pressures can reach thousands of pounds per square inch, a paintball is a fairly large but fragile projectile which can only stand limited amounts of pressure and force. Sectional density and frictional coefficient play some part in this, but it has been a long time since I cracked open a physics book so I can't do the math anymore, but I think I am on the right thought path. I would suggest a more efficient regulator to maintain constant velocity and a low pressure kit to increase shots per fill. When all is said and done, we are really dealing with a less that perfect projectile and launching system, but it has come a long way from back in the day when I first started playing and all we had was CO2 cartridges and 10 shot pump guns.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Mar 21, 2008 7:52 pm 
Offline
WO 1

Joined: Thu Jul 19, 2007 9:09 pm
Posts: 1390
Location: Carolina Border
Armson barrels copy H&K progressive polygonal rifling. The rifling twist actually increase towards the muzzle. If I'm not mistaken they are hammer forged as well.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sat Mar 22, 2008 7:26 am 
Offline
E-3 Specialists
User avatar

Joined: Mon Jan 28, 2008 4:16 pm
Posts: 68
Location: Salem, WI
I have an Armson barrel, and you are correct that it is polyagonal rifling, about 30 sides, no where near the hexagonal design used in firearms, it is more of an imperfect circle. I checked mine by lodging a paintball at several locations down the barrel then backlighting the bore. Light still passed by the ball at the corners of the angles, so the ball was not conforming to the barrel to a point where it made a perfect seal. This may be different when the ball is in motion however one could test the idea by coating the inside of the barrel with a light marking agent, shoot one ball down the barrel and check how much marking agent is left in the barrel. I would suspect the corners of the rifling will have marking agent and the walls will be clean. There has been much debate over the years reguarding ball spin and flight characteristics of paintballs, AGD did an extended study including building a gun that spins paintballs and maintains the spin on the semi-fluid center and they proved that rotational spin perpendicular to the direction of travel has little to no stabilizing effect on a paintball. So to me the idea of rifling a paintball barrel is nice, but has no real effect. My Armson shoots just as good as any other barrel with a good paint to barrel match and cosistant velocity. I know everyone has their favorite barrel and those who prefer rifled barrels will swear they shoot better, but there is no science to back up their claims. Now the back-spin effect has been document and used on many barrels like Apex and Flatline, but those are totaly different dynamics. More like the effects of a Curve Ball or a Slider in baseball, or Back-Spin and English in pool.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sat Mar 22, 2008 10:24 pm 
Offline
WO 1

Joined: Thu Jul 19, 2007 9:09 pm
Posts: 1390
Location: Carolina Border
Yeah I've read the debate on rifling so many times I'm sick of it. One day I going to spend the money to do some high speed photographs of a paintball going down a clear Lexan barrel and see what is really going on.

On an interesting note though, Bob Long came up with something called a cyclone bolt. I used to make the for him. He claimed that it imparted a torsional spin on the paintball. I had my doubts about that but ..... if you put an Armson barrel on a gun with a cyclone bolt, it would turn just about any gun into a paintball breaking machine. Even when you could get balls out of it the accuracy was horrible.

Interesting.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 23, 2008 8:15 am 
Offline
E-3 Specialists
User avatar

Joined: Mon Jan 28, 2008 4:16 pm
Posts: 68
Location: Salem, WI
High speed footage would be cool, maybe someone on the forum is in a photography class and has access to that kind of equipment. Hint-all those engineering/fluid mechanics/photography buffs who want an extra credit project jump in here. I remember the Bob Long guns, man that was years ago, is he still in the business or I'm I just living under my mil-sim rock? I would suspect that the ball is slightly deformed as it travels down the barrel, depending on how tight the fit is, and then snaps back into shape as it leaves the barrel. No rocket science there, but it would be cool to see. I think the seam around the two hemispheres is the main issue. You never know where it will fall in the barrel, so the forces on the ball are always changing in relation to the axis of the seam. I'm sure you have seen the fin stabilized pepper balls for law enforcement, those things are fairly accurate from what I have seen, but I'm drifting off topic.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Mar 23, 2008 9:48 pm 
Offline
E-2  PFC

Joined: Sun Feb 10, 2008 5:30 pm
Posts: 25
Location: Central Alabama
I wasn't refering to rifling to put spin on the ball, I was just talking about inner diameter shape for a tighter fit. If I remember my geometry correctly a polygonal shape would have less places for air to escape from around the paintball. The main problem, as stated before, would be if making sure there is enough room for the paintball to go through the barrel without negating any benefits to the design.

_________________
"There are no dirty tricks, just effective tactics."


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Mar 24, 2008 8:33 am 
Offline
E-3 Specialists
User avatar

Joined: Mon Jan 28, 2008 4:16 pm
Posts: 68
Location: Salem, WI
Yes we got off on a tangent there, sorry geometry pun, but I will point out that a spherical paintball being pushed down a circular tube all ready has the least amount of space between the ball and the tube, because there are no direct angles in the circular tube. It's like the old saying "Your trying to put a square peg in a round hole" but you are trying to put a round peg in a polyagonal hole, I think it defeats the purpose of what you are trying to accomplish. I addition, your ammunition is effected by chages in temperature, barometric pressure and humidity so it is never a constant size, nor is it a perfect sphere. Your paint to barrel match may be great one day and suck the next just based on the weather or inconsistancies in the manufacturing process. That being said, I think we should strive for "as good as it gets" because perfect is not going to happen but once in thousand shots, and work around the short falls of the ammunition. I recomend a "Freak Barrel" back with whatever front you choose if barrel to paint match is a concern for you. The tiny amounts of air effecincy you gain will unfortunatly be wasted somewhere else in the gun or air system durring the firing sequence because the breach is not perfectly sealed and the gun will always be set to use more air volume then needed to fire the paintball. It is a fine theoretical concept but the engineers design things based on a balance of performance vs. price point so the level of performace you are looking for will be way out of the normal price point and therefore nonviable to a business or company. I run into this problem all the time with my own designs and have to do a reality check by looking in my wallet and asking "do I want to spend that much to have a little better?" Sometimes the answer is yes, other times no, but you will have to make that decision for yourself.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Apr 16, 2008 8:34 pm 
Offline

Joined: Thu Dec 27, 2007 11:36 am
Posts: 1
reapercustompaintball wrote:
I remember the Bob Long guns, man that was years ago, is he still in the business or I'm I just living under my mil-sim rock?


Im probably going to get flogged to death for posting a speedball gun, but its an 06 Bob Long Intimidator. Yes, he is still around, and kicking ass. I almost picked this up with birthday monies

Image


Top
 Profile  
Reply with quote  
 Post subject: Re: Hexagonal Barrel? ? ?
PostPosted: Thu Jan 11, 2018 5:50 am 
Offline

Joined: Fri Dec 08, 2017 11:35 pm
Posts: 9
Hi, I'm starting a new site for this site.



goldenslot


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 5 hours  


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum


Search for:
Jump to:  

Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
For any questions, comments or concerns please feel free to contact the Admins at MilSim Empire Admins