Years ago, there was a guy (Don B.) who made bloops. he made one with an insert that vented the gases outward to ports of the tube. it was his first design, and I did some testing with it. I also blocked the ports on some of the tests and got some really surprising results. on one rifle it made the shots go about 10-feet to the right. even Don couldn't understand why. every other rifle it worked fine. using this bloop I got decent results. nothing where I would say would be breakthrough.
Later with his carbon fiber bloop results were better as weight was reduced to under 12oz. total if I remember.
here is what it looked like.
View attachment 1505136
In fairness I didn't do a lot of testing with it as at the time Don sent me this to test I already transitioned to lite weight tuners of under 5-oz. he did make a carbon fiber body tuner which I was excited about as with a bloop the whole setup would be under 8-oz. I never got to test one of those as Don seemed to have dropped out of the shooting scene. here is what it looked like with my notes on getting a secondary adjustment ring put on one.
View attachment 1505137
Le
Don’t know for sure but I’d suggest that defies the laws of physics. Expanding gases are just that….expanding.Hi Lee,
John (VLNBYR) sent me this pic awhile back. He likes to tape the ports off. Note how the tape was sucked in and not out how we'd think
View attachment 1505201
Again not my pic. I have no reason to believe that John intentionally try to mislead me or anybody else. What do you think would cause such a phenomenon to happen? I assumed the velocity of the bullet passing through somehow created a vacuum effect. Could it be enough to overcome and offset the pressure that's driving the bullet?Don’t know for sure but I’d suggest that defies the laws of physics. Expanding gases are just that….expanding.
I would think after the gases largely vacate the tube, it creates brief low pressure inside and outside atmospheric pushes in.
For me, irrelevant since I’m not a tube advocate.
Never spent much time with it either way but I've seen bloops where I glued very thin tissue over the holes and fired the gun. The paper indicated a vacuum and a couple of RF BR rifles, with the paper pulled inward at the holes. I'm saying nothing more or less than just that and not drawing any conclusions as to why, what for or even trying to explain it. Just what I've seen and that's all. I think there are more important things to worry about but I did fin that interesting.Again not my pic. I have no reason to believe that John intentionally try to mislead me or anybody else. What do you think would cause such a phenomenon to happen? I assumed the velocity of the bullet passing through somehow created a vacuum effect. Could it be enough to overcome and offset the pressure that's driving the bullet?
Pat, two things come to mind here, and one of them is NOT John misleading anyone. Your vacuum theory holds water for me. "Could it be enough to overcome and offset the pressure that's driving the bullet?" Yes, it could be. When the bullet and all the pressure driving it goes through that tube, what is venting it? Nothing, the bolt is still closed. Fill your lawnmower up with your plastic gas can with the vent closed. What happens? The pressure of the flow causes something I am very familiar with (retired boilermaker), a pressurized vessel. That pressure sucks the sides of gas can in until the material can't overcome it and it 'glugs' to get some air before the flow starts again. Now, I do not know that's the cause, not empirically from data, but plausible non the less. The second thing, and I have shot with John a lot, including many matches where we were bench partners. John screws different tubes on and off rifles all the time. That material, as most can see, is aluminum duct tape which is very soft. I would venture a guess John's hand created those depressions in that tape from screwing that tube on and off.Again not my pic. I have no reason to believe that John intentionally try to mislead me or anybody else. What do you think would cause such a phenomenon to happen? I assumed the velocity of the bullet passing through somehow created a vacuum effect. Could it be enough to overcome and offset the pressure that's driving the bullet?
No, I suspect that’s his thoughts on the matter.Again not my pic. I have no reason to believe that John intentionally try to mislead me or anybody else. What do you think would cause such a phenomenon to happen? I assumed the velocity of the bullet passing through somehow created a vacuum effect. Could it be enough to overcome and offset the pressure that's driving the bullet?
Alas, one of the unsolved questions of the universe.@doclu60
Scott, John sent me that pic via text to illustrate that the vent holes draw air in and not push it out as I might have (or might not have lol) stated on RFC. I honestly don't remember if I said something to solicit the picture or someone else did. All I know is he sent me that pic with a message that said air is sucked in the openings and not sucked out. John told me awhile back that he uses aluminum duct tape to cover the vent holes when we were chatting about a Noodle that John Crowley lent me. So I knew the pic was from one of his rifles and I'm certain it's not pressed inward from him screwing the tube onto the tuner
@TRSR8
Tim, those were my thoughts, not John's
Anyway, I hope you all have a Merry Christmas as well
This isn't the proof implied. Four 20 shot strings with different average MVs only shows that different averages can be experienced, not that the tube had any role.here is one for the theorists, seems the tube increased the velocity
Vudoo single shot, 26 inch Benchmark barrel, Harrel Tuner, JPappas vented tube, 57 F, SK Semi Auto ammo
no cleaning was done during the test. ProChro optical 12 feet from muzzle with sunshade
5 shots to season the barrel no data recorded
20 shots with tuner and no tube Velocity 1113 FPS - ES 26 FPS - SD 8 FPS
20 shots tuner with tube but no ring Velocity - 1125 FPS ES 34 FPS SD 8 FPS
20 shots tuner and tube ring on the rearmost set of holes Velocity 1121 FPS ES 29 FPS SD 9 FPS
20 Shots tuner and tube ring on the middle set of holes Velocity 1126 FPS ES 47 FPS SD 12 FPS
I plan on it, I have a small FX chrono in the mail I am planning on using in another project involving atmospheric temperature and FPS which I will use to investigate the tube effects also.This isn't the proof implied. Four 20 shot strings with different average MVs only shows that different averages can be experienced, not that the tube had any role.
Try shooting several four 20 shot strings without the tube and see if the average MV remains constant.
Hi Pat,Hi Lee,
John (VLNBYR) sent me this pic awhile back. He likes to tape the ports off. Note how the tape was sucked in and not out how we'd think
View attachment 1505201
Yeah, I thought bullet strike at first, but it didn't do it on other rifles. I am trying to get that bloop back not for use but more of a keepsake. I gave to a friend who passed away last May, and the family is going through his things. so far only the 1-piece rest I made I was able to get back.Don’t know for sure but I’d suggest that defies the laws of physics. Expanding gases are just that….expanding.
I would think after the gases largely vacate the tube, it creates brief low pressure inside and outside atmospheric pushes in.
For me, irrelevant since I’m not a tube advocate.
Good point. there is air in front of the bullet. like a water the column of air could cause the vacuum effect to draw air in from the ports.My guess on why tissue or foil is sucked in on a bloop tube - venturi effect. Just like your pressure washer sucking cleaning solution into the pressure stream.
Let’s remember, Don tried every variation under the sun, all, as I recall, with zero testing. He made whatever came into his mind that particular day.Good point. there is air in front of the bullet. like a water the column of air could cause the vacuum effect to draw air in from the ports.
I suspect this is why Don made the diverter insert for his bloop to direct this air column out of the ports inside of letting it get pushed down the barrel and cause the vacuum effect.
Lee
Tim, I did some testing for him as he wanted some feedback on what he was doing. we corresponded a bit about tuners and bloops. I know he made a bunch of bloops for Marty.Let’s remember, Don tried every variation under the sun, all, as I recall, with zero testing. He made whatever came into his mind that particular day.
He would literally do 3-4 different versions within a month or so.
It was like a flame….it flashed…..it died.
He was driven by what “might” work.
