How important is seeing the hit

Discussion in 'Videos Of Tech Stuff And Reviews' started by J E Custom, Nov 11, 2013.

  1. J E Custom

    J E Custom Well-Known Member

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    This is another video I had promised.

    In this video the effects are clearly evident if the wrong brake is used/chosen for light weight barrels.

    I have no evidence of the effects on bedding because this has just been identified and long term effects are not known.

    We messed with changing the top port size by plugging all but one and on one we plugged all 4 and the results were not conclusive . The 1 that we plugged all but one still exhibited excessive down force and the one that we plugged all top ports acted normal for one that did not have any top ports in the beginning (No Big Surprise)

    It appears that if you want this feature you should start with one very small hole and ream as you test it, enlarging it just enough to hold the muzzle down and No More.

    I like everyone else, thought this was the cat's meow, until I started seeing the results in slow
    motion. This could also explain the broken stocks .

    So hear are the results for everyone to see so they can decide what they want from a brake.

    Nothing personal or pointed, just more information.

    [ame="https://www.youtube.com/watch?v=_W4HviShfEs"]How important is seeing the hit? - YouTube[/ame]


    J E CUSTOM
     

  2. CB11WYO

    CB11WYO Well-Known Member

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    Dang, that's interesting.

    Makes sense, "for every action there is an equal and opposite reaction"... :) Be it vertical or linear
     

  3. cowboy

    cowboy Well-Known Member

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    Wow - that is an eye opener. Scariest part is that it makes perfect sense. How the heck would you tune a brake with top ports, trial and error?
     
  4. trebark

    trebark Well-Known Member

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    awesome...very informative
     
  5. TH

    TH Well-Known Member

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    Thanks for taking the time to put together an educational video. Would be interesting to see what would happen if you did the same test with a suppressor.
     
  6. gamehawker

    gamehawker Well-Known Member

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    Great information.

    Thanks!
     
  7. J E Custom

    J E Custom Well-Known Member

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    That's pretty much what it would take.

    I figured on trying a very small hole and using the camera and keep drilling /reaming it until it was neutral.
    (A long slow process for sure) or tap one hole and try different plugs with different size holes in them.

    The problem with that , if you wanted to change loads it would change again.

    So I just decided to do without top ports and practice follow through on each shot.

    On The one 300 that was bending the stock, we discontinued testing in fear of braking the stock.

    J E CUSTOM
     
  8. J E Custom

    J E Custom Well-Known Member

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    I would think that a suppressor would not have any down force because all of the exit holes are in the front (I Think).

    J E CUSTOM
     
  9. Neff991

    Neff991 Well-Known Member

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    Very interesting information and I'm glad you shared it with us all. I'm also glad I didn't go with a top ported break!
     
  10. geo4061

    geo4061 Well-Known Member

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    J E once again you amaze. Thanks.
     
  11. J E Custom

    J E Custom Well-Known Member

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    Thanks geo4061 for your kind words. I mostly do my experiments for my own education, But some time a feel I have to share the results with others if it is beneficial.

    The slow motion Videos work well in most cases to show things that the eye normally cant see. If you notice in the Video, we moved the restraint on the last rifle to control the stock flex because we were worried about breaking it. It still flexed the wrist area so we discontinued testing it in fear of braking a very expensive stock.

    Heavy barrels are less flexible so the down force is transferred to the stock causing this reaction. this is a Sendero Taper and Is stiff enough to flex the stock.

    This test also explained why accuracy fell off in light barrels with large/heavy bullets, Even if they didn't have a muzzle brake the barrel twisted and/or flexes hitting the stock even when floated.

    I am glad everyone enjoyed the Video.

    J E CUSTOM
     
  12. toddc

    toddc Well-Known Member

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    My brake on my 7SAUM has 4 small ports on top. I threaded them all. Ended up with 3 plugged and 1 open for the most NEUTRAL shot. You could even run reducer bushings in 1 or several to further tune. I did this and also slightly cocked the side ports to counter twist in recoil with the longer bearing surfaces. I'm happy with my results.
     
  13. J E Custom

    J E Custom Well-Known Member

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    That's probably the best way to fix this problem. We looked at other ways and to "Tune" the brake
    threading one hole and using threaded bushings with different size holes was the best way.

    Also to show how much effect the location had, we moved the ported bushing from the front hole to the back hole (4 top port holes) and there was a change in POI (the location appeared to effect the harmonics differently) accuracy seemed to be the best when the back hole (Nearest the receiver)was used for the top vent. This was probably due to the difference in the moment arm (Length)of the port to the receiver.

    This led to the conclusion that if it made that much difference, We needed to compare the Tuned port brake to the same brake with all the top ports plugged for accuracy. Test showed that the brake with all the ports plugged shot the best group (More accurate even though it was very small).

    This led us to the conclusion (At least with the test rifle)that the un opposed port, even though it resolved the muzzle rise/drop problem. was causing differences in the harmonics effecting accuracy and with the same loads and the same SDs and ESs. when all forces were in line with the bore, they seemed to have less negative effects.

    I do feel that with good loads these effects can be negated/controlled to have little or no negative
    effect on accuracy. Also keep in mind that the bullet is in the process on leaving the brake before any on these issues have much of a chance to cause issues with accuracy.

    Neutralizing barrel flex has nothing but plus's for the bedding and the stock.

    J E CUSTOM
     
  14. Ytsheephnter

    Ytsheephnter New Member

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    Very interesting topic. Thanks for sharing.