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Speed of factory loads

Discussion in 'Shooting Related Threads' started by stilltrying, Sep 13, 2011.

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  1. stilltrying

    stilltrying Member

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    Today a friend fired a number of factory loads through his Chrony Chronograph to find how fast they were going. Bright sun no clouds. All were and ounce and 1/8. The gun club 2 3/4 dram were 1100fps. The 3 dram gun club were 1149 fps. The Estate 3 dram were 1100 fps. With an ounce and 1/8 of shot I was lead to believe the following: 2 3/4 dram was 1145 fps and 3 dram loads were 1200 fps. Have I been misinformed? What factory loads go as fast as they claim? It looks like I will have to buy a chronograph and work up my own loads.
     
  2. BigM-Perazzi

    BigM-Perazzi Well-Known Member

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    Still, the factories use a different type of chrono for one. They also have a very wide tolerance on their speeds.

    A lot depends on the distance. I generally use 6 ft which often duplicates the factory speeds. Then my reloads are measured against that. Not the most scientistic but works for me.
     
  3. Dr.Longshot

    Dr.Longshot Banned Banned

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    Where was he standing when he shot, how far back? Did he use the sun sheilds?

    This is actually all relative, I shoot over a Pro-Chrono, not the one that folds up.

    The very fist AA Silver Bullet with the double ++AA++ chronographed 1420
    talk about knocking the snot out of you, we used them for long shootoffs.

    Gary Bryant
    Dr.longshot
     
  4. miketmx

    miketmx Well-Known Member

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    I recently bought 2 flats of Gun Clubs 2 3/4 dram 1 1/8 oz and I thought they had more recoil than comparable Federal Top Gun shells.
     
  5. VNVET

    VNVET Member

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    Chronographing a shotgun is different than a rifle or pistol round. Your setup is critical and even then marginally accurate. Unless the Shooting Chrony has improved over the years, their accuracy is questionable. The URL (link) above will give you everything you need to know about chronographing a shotgun.

    Jim
     
  6. RickN

    RickN Well-Known Member

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    I think you need to chrono those loads again. Cloudy is actually better than bright sun I've found.
     
  7. MKillian

    MKillian TS Member

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    Tom Armbrust has told me more than once that the factory builds its loads to a ±100 fps tolerance of each velocity step.

    Mike Killian
     
  8. Johnny

    Johnny Well-Known Member

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    stilltrying, Those numbers can't be right. Place the Chrony in the shade and try again.
     
  9. stilltrying

    stilltrying Member

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    I am going to try someone else's chronograph on Saturday. The fps is printed on the boxes! Gun club shells recoil like they are hot!
     
  10. BigM-Perazzi

    BigM-Perazzi Well-Known Member

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    Gun clubs do feel hotter than top guns to me also...
     
  11. AveragEd

    AveragEd Well-Known Member

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    Those who said that clocking shotshell loads differs from single-projective loads are correct.

    You must have the muzzle of a shotgun (except with slug loads) closer to the chronograph - my chronograph manufacturers recommend no farther away than five feet. You basically want to be as close as possible without muzzle blast affecting the readings. That's because "hobby" chronographs like almost all of us use are calibrated to clock one object, so they clock the leading pellet instead of the mass of pellets like more costly devices made for use with shotshells. The closer to the photocells the muzzle is, the less strung out the pellets have a chance to become. Accordingly, they tend to clock shot loads a little faster than actual speed - one of my manufacturers suggests subtracting 35fps from the readings.

    However, you're experiencing unusually low readings, so I agree with those who suggest trying again under shaded conditions. Even with rifles, I find my readings somewhat suspect under bright, cloudless skies and even have had two chronographs give either no readings or wildly inaccurate ones in bright sunlight. I have a 10'x10' canopy I place my chronographs under when I have to use them under those conditions. I know, some chronograph manufacturers disagree and one even told me the device cannot work in shaded conditions but my experience has been contrary to that advice.

    Ed
     
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