PPS Blazer Barrel = 'Elliptical Honing' ...does it work?

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  • Jack & Coke
    TUNAMAX No. 1
    • Jul 2002
    • 2644

    #1

    PPS Blazer Barrel = 'Elliptical Honing' ...does it work?

    Interesting read regarding the elliptical honing of Palmer Pursuit Shop's barrels for their gun, the BLAZER:

    From: http://www.palmer-pursuit.com/techpages/Palmerinfo2.htm


    Glenn Palmer says that it is most important (for accuracy) to match the barrel to the output of the valve.

    Huh? Read on...

    Really, this is another way of saying you need a good paint to bore fit. Not too tight, and not too loose. A paintball will deflect radially (get bigger) when pressure is applied by compressed gas. The pressure output of the valve rises, peaks and then falls. It is not a digital on/off device. If the valve output pressure rises, peaks and falls, then the paintball diameter will rise, peak and fall. This makes it impossible to get a good paint to bore fit with a straight-profile (constant I.D.) barrel.

    A good example of this is when you get ball breaks halfway down the barrel with a high-pressure gun and a straight profile barrel. Enter the elliptical profile barrel. The inside diameter of an elliptical-profile barrel is tight at the breech, loose down the middle, and tight at the muzzle. Sound familiar?

    The elliptical-profile barrel allows a good fit of the paintball to the barrel all the way down its length. The vented barrels are tight all the way through the venting, so the bulge is closer to the breech of the barrel. I believe this only applies to high/medium pressure guns like the Typhoon. It would seem that the benefit of elliptical honing diminishes with low-pressure guns that don't deform the paintball as much. With low-pressure guns, a properly fitted straight-profile barrel is all that is required to achieve the same quality of paint to bore fit.

    The goal of the hone/shoot/rehone process was to get the balls to come out with no spin. It follows that a good paint to bore fit will produce less spin than a bad one. Spin detracts from accuracy at long ranges, as the paintball slows down, the spin becomes the dominant force. This produces the "hook" shots you get out of lesser guns. A paintball with no spin acts like a "knuckleball" in baseball, causes it to wiggle back and forth, up and down along its path. This wiggling will keep the ball close to the initial path, at all ranges. A spinning ball will be closer to the path at close ranges and further from the path at long ranges.

    Very interesting theories regarding the physical dynamics of paintball ballistics...

    What do the brain trusts of AO think?
  • cockermongol
    Registered User
    • Jul 2003
    • 227

    #2
    makes since if it's true that a paintball will really expand at mid-barrel. seems like that type of thing would be impossible to measure...

    Comment

    • Jack & Coke
      TUNAMAX No. 1
      • Jul 2002
      • 2644

      #3
      well, for what it's worth...

      Look at these high speed photos AGD took of paintballs as they are fired through a clear barrel at regular velocity:









      read more about it here: http://www.automags.org/forums/showt...threadid=34429

      The ball does not appear to ever be 'deformed' during flight.

      Comment

      • Doc Nickel
        Unrepentant Gadget freak

        • Jul 2001
        • 499

        #4
        We're still arguing distortion? Sheesh. Okay, let's try this...

        First off, how much does the ball distort? To answer this, I whipped up a quickie little aluminum doodad. It has a flat-bottomed .750" hole and a cross-drilled hole for a dial indicator. I used a .0005"-graduated indicator, held in by a firm press-fit. The paintball goes in the big hole and the spring-loaded indicator shaft holds it against one side.



        I zeroed the indicator dial and put the works in my handy-dandy arbor press. The paintball, in this case, when resting against the bottom of the hole, stuck up by almost exactly 0.075".



        All that remained was to squash the ball in the press that seventy-five thousandths.



        Total gain in "bore" diameter of the ball: just over 0.0035", or three and a half thousandths of an inch.

        Is this a "realistic" test? No: Firing the ball for real applies pressure over the entire half of the ball, the entire hemisphere facing the bolt. This test focused the pressure on two flat surfaces, exaggerating the distortion. In a paintball gun, the burst of air would spread out to conform to the entire half of the paintball, reducing the forces to a minimum.

        Also, I was forcing the ball into a hard surface. In the paintball gun, the only resistance facing the ball is the ball's own inertia and the very minor drag- if any- from the bore itself. In other words, it has only an open barrel to hold it back.

        So unless I'm missing some interesting factor, it looks to me like, if we give the ball the absolute worst possible conditions in an effort to induce distortion, we get only .003" to .004" change.

        And those conditions are not replicated when actually firing a ball- conditions in which case are actually optimized to reduce distortion.

        While I won't declare the matter "closed" just yet, I believe we can very accurately say that the paintball does not distort to any appreciable degree when fired, nor in flight, and by no means enough to have the barrel attempt to "follow" that pattern of distortion.

        Doc.

        Comment

        • Doc Nickel
          Unrepentant Gadget freak

          • Jul 2001
          • 499

          #5
          Oh, and one other thing:

          Palmer's "eliptical hone" is "football" shaped- the bore is very slightly wider in the middle of the barrel, and thinner at both the breech and muzzle ends.

          However, even if we assume that the air burst is enough to distort the paintball, where will the point of greatest distortion come? According to this chart:



          The peak pressure comes pretty much before the ball starts to move, and drops off sharply thereafter as the space between the bolt and ball increases.

          Therefore, if Palmer's above-quoted concept of why their eliptical hone works, the largest portion of the bore should actually come at the breech, and it should taper down to the smallest about 2/3rds of the way towards the muzzle. It would need to be cone shaped, not football shaped.

          Palmer does make some nice barrels, sure, but lets not call it magic or make up some SP-like terminology to explain it, eh?

          Doc.

          Comment

          • Jonesie
            All Around Good Guy
            • Oct 2002
            • 1123

            #6
            Nice posts guys! VERY informative. J&C can really come up with some thread topics, no?

            And Doc blinded me with science!
            David M. Jones
            AO Member #1111 - Formerly davej946
            Member of Team AO, MGO 2003

            Wildfire :: Division III X-Ball
            www.wildfirepaintball.com

            Supported by:
            Wildfire Paintball
            Nelson Paintballs

            Comment

            • cledford
              Registered User
              • Feb 2001
              • 1386

              #7
              Glen and Tom got into this in the Deep Blue flight physics thread.

              Glen SWEARS by the elliptical honing yet will freely admit that his testing consists of nothing more then a gauge, a chrono and his eyes. If he can see it, he believes it - but I don't find that good enough for a guy of his stature. I'm not bashing Glen Palmer - I admire him as much as Tom, only for different reasons. That having been said, Glen (by his own public admission) doesn't put anywhere near the amount of research into his stuff that I thought that he would have. I was pretty surprised.

              I'd still like to have one of his products as they're handcrafted pieces of paintball "metal-art."

              -Calvin
              Last edited by cledford; 02-06-2004, 08:13 AM.
              From a poster at PB Nation:

              ""Jim, back to your cave. Bob Long is on the batphone..."

              MY FEEDBACK

              Comment

              • thei3ug
                Canicus
                • Oct 2000
                • 846

                #8
                the way he tests his barrels is enough to figure out whether they work or not... elliptical honing or no. keep in mind he HAS to rehone them... they're soldered on to his guns!

                as for saying he's gone, when did he do this???
                [*img]http://userpic.livejournal.com/11885469/469200[/img]
                Filesize too large- Tato
                Greatest "Sponsor" Ever.

                Comment

                • cledford
                  Registered User
                  • Feb 2001
                  • 1386

                  #9
                  He said this a month ago - he was possibly only refering to Deep Blue:

                  Exactly why you haven't seen me participating in Deep Blue lately

                  from: http://www.pbnation.com/showthread.p...1&pagenumber=5

                  I'm changing my post above, I mis-stated his position.

                  -Calvin
                  From a poster at PB Nation:

                  ""Jim, back to your cave. Bob Long is on the batphone..."

                  MY FEEDBACK

                  Comment

                  • thei3ug
                    Canicus
                    • Oct 2000
                    • 846

                    #10
                    oh yah. i forgot about that. doh.

                    oh well, i'll just keep sticking around POG.
                    [*img]http://userpic.livejournal.com/11885469/469200[/img]
                    Filesize too large- Tato
                    Greatest "Sponsor" Ever.

                    Comment

                    • Jack & Coke
                      TUNAMAX No. 1
                      • Jul 2002
                      • 2644

                      #11
                      Great post Doc!

                      cledford nice thread too (pbn)

                      Comment

                      • ForgedSpeed
                        Registered User
                        • Nov 2002
                        • 165

                        #12
                        Am I missing something here.. because it seems to me one could just hook up a normal barrel and eliptical barrel to a gun, test the accuracy and that would be the end of it.
                        My Feedback

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                        • Muzikman
                          Everything AGD
                          • Dec 2000
                          • 6229

                          #13
                          Not quite that easy...

                          Comment

                          • Ityl
                            Registered User
                            • Nov 2000
                            • 706

                            #14
                            First of all, I wouldn't rule out something because high school physics says something happens a certain way. When I took physics in high school (2000-2001) we were neglecting friction.

                            Secondly, a paintball traveling at 300 fps with no spin can only travel so far. The Flatline barrel for the Tippman 98 shows that spin on a paintball can affect range, there is NO way you can argue against that.

                            Thirdly, this barrel design could just make a ball exit the barrel in a more consistent fashion, therefore increasing accuracy (well technically precision).

                            This isn't directed to anyone specifically. Just remember there is more to the world than High School physics.
                            I like potatoes

                            Comment

                            • Butterfingers
                              PhD in Automagology
                              • Jan 2001
                              • 2263

                              #15
                              The burnouli effect as in the tippman flatline does NOT increase range and Ill tell you why...

                              It is an aerodynamic effect that increases loft thus it brings the range of the paintball into the feild of view of the shooter.

                              You can easily get as much range with a normal marker by tilting the barrel up plus it will break easier at the end of its travel.

                              If you tilt a flatline barrel up there will come a point that the loft will just send the ball straight up.

                              High school physics are 100 percent correct PROVIDING it is used in the PROPER context.
                              Did you hear about the new european weapons contracts? France is going to make the wooden sticks Spain making the little white flags

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