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Thread: CCI 200 primers causing slower velocity?

  1. #11
    Quote Originally Posted by mtnbkr View Post
    oh! Well, that's different.

    ok, same gun, same powder charge.

    Safe to assume same brass and same bullet? What about brass prep and seating depth?

    Since you asked about the primer, are you using different primers?

    Chris
    Same rifle. Same brass, primer, and charge. I load both the 195s and the 178s to 2.87" (as long as I can).
    #RESIST

  2. #12
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    Quote Originally Posted by LittleLebowski View Post
    Same rifle. Same brass, primer, and charge. I load both the 195s and the 178s to 2.87" (as long as I can).
    To what depth does JV load them?

    Are you using powders from the same lot? Test environmentals (ambient temp, humidity, etc) the same (or close, as in not a 30+ deg difference)? Are you using the same chronograph?

    Are you *sure* the charge is the same? Maybe pull one loaded by each of you and measure the charge on the same scale. Your individual tools may be off. Digital scales have a .1gr variation in either direction for example.

    Chris

  3. #13
    Excellent questions, answers inline.

    Quote Originally Posted by mtnbkr View Post
    To what depth does JV load them? I think he pushes it to mag length like me. I'll run over to his office and find out.

    Are you using powders from the same lot? Yes, same keg. Test environmentals (ambient temp, humidity, etc) the same (or close, as in not a 30+ deg difference)? Yes, all the same. Are you using the same chronograph? Yes.

    Are you *sure* the charge is the same? I checked on two digital scales and an RCBS beam scale, they are all within .08 of each other.
    Last edited by LittleLebowski; 05-29-2018 at 09:04 AM.
    #RESIST

  4. #14
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    Quote Originally Posted by LittleLebowski View Post
    Excellent questions, answers inline.
    If the components are the same, you're using the same charge (verified by multiple scales), and your seating depth is the same, the ONLY other thing that comes to mind is brass prep (trimming, chamfering, sizing, etc) and age (new vs N-Fired). To be honest, I'd expect brass prep and age to have more of a factor on accuracy than velocity, though I suppose old brass with non-elastic necks could reduce velocity since the bullet wouldn't be held long enough for appropriate pressures to develop. I'm not sure that's a rifle issue as much as it is with handguns.

    What about loading dies? Same brand? Maybe the brass is being worked slightly differently (tighter/looser necks, shoulders bumped back more or less, etc).

    Aside from velocity concerns, how is accuracy?

    Otherwise, I'm at a total loss to explain the difference in velocity.

    Chris

  5. #15
    JV figured it out, I was checking velocity with the can on. I'm going to chrono sans the can and report back, but I bet that's it (the Magnetospeed "bayonet" needs to be close to the muzzle, within 1 centimeter). Of course this negates me running the chrono in my back yard now
    #RESIST

  6. #16
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    Have him chrono his loads with the can and see if his loads react accordingly.

    Chris

  7. #17
    Quote Originally Posted by mtnbkr View Post
    Have him chrono his loads with the can and see if his loads react accordingly.

    Chris
    He's a busy guy, I'll just figure it out with my can and my loads, I doubt he'd deign to shoot my ammo
    #RESIST

  8. #18
    German Salazar performed an extensive primer test, and posted the results on his old website: riflemansjournal.blogspot.com. He has since take the site down. Some of his photos are still available at: http://www.6mmbr.com/PrimerPix.html
    "Government is not reason, it is not eloquence, it is force; like fire, a troublesome servant and a fearful master"

  9. #19
    Quote Originally Posted by Triggerf16 View Post
    German Salazar performed an extensive primer test, and posted the results on his old website: riflemansjournal.blogspot.com. He has since take the site down. Some of his photos are still available at: http://www.6mmbr.com/PrimerPix.html
    I regret missing that site, I see so many references to excellent work on it.
    #RESIST

  10. #20
    Site Supporter Hambo's Avatar
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    So if I understand this you and JV have similar rifles, and using the same data your loads were slower in your rifle than his were in his rifle. That it?

    If you want to compare his chrono data to yours, you really need to shoot his ammo in your rifle. Otherwise there are rifle variables you can't account for. If his ammo hits X velocity in yours, but your ammo doesn't reach X, it's something in your ammo.
    "Gunfighting is a thinking man's game. So we might want to bring thinking back into it."-MDFA

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