Barrel break in

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by backcountryguide, May 11, 2013.

  1. backcountryguide

    backcountryguide Well-Known Member

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    Guys my new Creedmoor is shooting lights out but my chrono results are interesting. The barrel is a Bartlein 1in8 twist 5r and Ive put 50rds through it so far with the 140 Hybrids on top of 43.5gr of H4350. Did a proper break in of shoot and cleans for 7 rounds at wich point the copper completely stopped. I am just wondering when it will settle in as far as velocity goes? I thought I would have reached that point. My Brux started shooting duplicates over the chrono around 35 rounds. gun)
     

  2. Broz

    Broz Well-Known Member

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    It might change a little in velocity out to 100 / 150 rounds. But it should be consistent now. Are you seeing large ES between shots? If so move your chrono out to 18' from the muzzle.

    Jeff
     

  3. backcountryguide

    backcountryguide Well-Known Member

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    Actually Im seeing duplicates of diffrent velocities for example 2825 duplicate 2844 duplicate and the last to went 2835 duplicate so I am thinking its my chrono. Thank you for fast reply Broz
     
  4. backcountryguide

    backcountryguide Well-Known Member

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    Any other advice on chrono setup Broz. I think my velocity should be a bit higher do to my tube being 28" long. I was thinking around 2850+
     
  5. Broz

    Broz Well-Known Member

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    No, just set your chronograph out at 18' from the muzzle. I would not get to concerned about what you see for numbers yet. I have had many chronographs lie to me over and over, especially less expensive units. That is until I bought an Oehler 35. Working out drops to 1000 yards will give a better idea of real velocity. The proof is in the pudding.

    Jeff
     
  6. elkaholic

    elkaholic Well-Known Member

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    Usually a Bartlein doesn't require much break in! You are probably where you are going to be, whatever that is........rich
     
  7. Bart B

    Bart B Well-Known Member

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    Unless your barrel's got the same chamber, bore and groove dimensions as the one the load recipe was developed with, your muzzle velocity can easily be 50 fps faster or slower than the data claims.

    And your powder and primer lots are not the same as what the load was developed with. This will often change chrono'd loads 25 fps different than what the manual says.

    Even with two people shooting the same rifle and ammo, a 25 to 50 fps difference in average muzzle velocity happens a lot 'cause the rifle's not held the same way by each shooter.

    It's rare that anyone duplicating a published load gets the same muzzle velocity quoted for it. Even allowing for a 25 fps change for each inch of barrel length difference.

    It's possible, but how does one compensate for the inaccuracies of virtually all scope adjustment values per click? All internally adjusted scopes of a given make and model do not have exactly the same amount of impact change per click. To say nothing about the atmospheric conditions between the rifle and target that'll change the bullet's drop and there's no way you can measure them when the bullet's fired.
     
  8. Broz

    Broz Well-Known Member

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    Well some of us do check for calibration by measuring what the scope actually moves the impact and adjust the ballistic program to it. I will trust my actual drops to a 100$ chorny any day.

    But what ever you say Yoda....:rolleyes:

    Jeff

    [ame="http://www.youtube.com/watch?v=fLrpBLDWyCI"]That is why you fail - YouTube[/ame]
     
  9. backcountryguide

    backcountryguide Well-Known Member

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    Lets assume that I am not a complete novice Bart and that I know about chambers,powder,primers and a thing or two about killing big bulls a long ways away. This is not my first custom rifle or barrel just my first 5r Bartlein. Broz I didnt meen to drag you into a piss match thankyou for your consrtuctive advice.
     
  10. Bart B

    Bart B Well-Known Member

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    If one measures scope adjustments without firing a shot, then all the variables in optics, humans and ammo are eliminated. Some know how to do this. Others don't.
     
    Last edited: May 13, 2013
  11. extreme

    extreme Well-Known Member

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    Got to say ,,,,Sometimes you are really funny.....Love this line,,, I have used it many times my self..
     
  12. Broz

    Broz Well-Known Member

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    No problem here my friend. I will just let Mr.B argue with himself. If we wish to hear more of it one could always just read his past posts as the majority of them are simply degrading comments or argumental.

    A little humor is good medicine once in a while. :)

    Jeff
     
  13. elkaholic

    elkaholic Well-Known Member

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    Ahhhhhcome on! Bart is just being Bart:D:D:D Aroyalpain
     
  14. extreme

    extreme Well-Known Member

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    We need a lot more of it..( HUMOR ).have a great day ..
    Pete