Bill,Originally posted by billmi
I believe such wider "tracks" on the ball could also be achieved by the ball pitching and yawing during its travel down the barrel. Many have taken it as a given that the ball will face some rotation when fired - if the ball does in fact distort to this semi-cylindrical shape, such rotation would not be possible. Thus "hook" shots caused by a yawing spin couldn't happen.
If you do the test as I described for yourself, you will see that the tracks or skid marks on the ball are to consistent to be made by a ball that is merely bouncing through the barrel as a result of yaw and pitch. If the ball did not seal to the bore and be held relatively straight, air blowing past the ball on one side would generate a great deal of spin as the other side would be slowed down by its contact with the bore. The same prinicple that generates the spin on the ball that goes through the curved and very large bore barrel of the Tippmann flatline barrel. The curve of the barrel forces the ball against the wall of the tube, creating friction while propulsion air can blow past the ball on the other side to amplify the spin. The biggest drawbact that I see in spinning a paintball is the fact that they are not round and feeding does not allow for the ball to be fed into the chamber with the seem of the ball in the same orientation to the axis of the barrel with each shot. By breach loading a paintgun to place each ball in the chamber with its seem in a controlled orientation to the barrel it is fairly easy to see how the flight of the ball is affected by the orientation of the seem when it is fired. When the seem of the ball is against the full perimeter of the bore; muzzle velocity is just a bit higher and the hits on target will be pretty much in the same group but with a somewhat vertical spread. When the ball is loaded so the seem is placed lineal to the axis of the bore, (starting with a 12 oclock and 6 oclock orientation) the center of the shot group will be in a different location on the target and show a more horizontal spread. Loading with the seem orientation changed on either axis creates shot groups in a clock-like pattern on target. Also noted in these same tests was that the less spin seen on the ball in flight, the tighter the shot groups; regardless of the orientation of the seem. Velocity and muzzle blast also plays a big role in the size of the shot groups.
It is important to note here that the first of the above tests was done with a known gun with an 11" barrel and precisely tuned valving but ran the same tests with a test bed unit in order to see the results of varying barrel and valve configurations.
I'm not saying that the ball flattens out like a pancake; it simply can't do that within the confines of the barrel. However, it dosn't take much "distortion" to make a big difference in how the ball acts when it is fired. Just as it takes only one small speck of paint, in an otherwise pristine barrel, to send a ball off into never-never land when shot.Originally posted by billmi
I've had a look at some of the high speed video and stills Tom has taken of balls fired through a clear barrel (some is included in the Automag RT video.) If the balls are distorting, it is too insignificant to see in the photographs. An important question to which I hope Tom can supply an answer is, where those done with gelatin paintballs, or with Perfect Circle paintballs, which have a more rigid plastic shell?
What I am saying, is that we need the ball to upset somewhat so that it can seal against the bore and achieve maximum potential from the internal balistics. However, we also need for the internal balistics to cease acting on the ball before it leaves the barrel if we are to expect any kind of consistency from a relatively innconsistent projectile.
Also, (in keeping with the thread) closed bolt firing seems to give me the best opportunity to to dial in my equipment and make the most out of every ball shot.
Thanks for your support Bill. I am about as old school and old fashioned as they come. I just can't operate on theory or conjecture besides having a starting point in the search for actual improvement. The bulk of what I know about paintball equipment and shooting paintballs has come from a great deal of trial and error and/or trial and success that has been focused only on how to get my own equipment to allow me to play my best game. When common sense thinking leads to a success a process will become a standard part of what we do and I will gladly share the results with others. I have also learned a great deal from my errors as well.Originally posted by billmi
Please also note, I will happily disagree with Glenn on theory or interpretation of the results of a test or experiment, but this in no way means I don't respect his viewpoint. There are a lot of people in the industry that will support a certain theory regardless of its validity, simply as a means to market their product. Basically they have a product, and whip up a theory to explain to you why it's the best in the world and you need to buy it. Glenn on the other hand, has used his theories of paintgun operation to build quality products, and is one of the few manufacturers/customizers to understand the concepts of old world craftsmanship.
See you on the field,
Sometimes it gets difficult to share something without it looking like a marketing ploy and many just do not understand that, that just is not my style. You know my views on common marketing practices because we have discussed it on a personal basis.