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Thread: Crowning Facts

  1. #1
    Member SureShot's Avatar
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    Crowning Facts

    Please teach me.
    I'm curious to learn more about the crowning of barrels on firearms and airguns. Does it only apply to rifled barrels and not smooth barrels?

    I thought that when a barrel was manufactured that the opening at the end of the barrel was simply that, an opening where the pellet/bullet exited the barrel but there's more to it isn't there?
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  2. #2
    Moderator rsterne's Avatar
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    Crowning is at it's simplest, just having the end of the barrel square to the bore so that every point on the pellet skirt exits at the same instant.... That avoids uneven venting of the air charge that could tip the pellet and disturb the flight....

    A 90 degree crown is, in theory, the best, but it is easily damaged.... To avoid that, various modifications have been made, including recessed crowns (where the outer part extends past a square area), 11 degree crowns (not quite square to the bore), and also some that are curved (which offer more protection), often found on production guns....

    Bob
    Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
    Airsonal: Too many to count!

  3. #3
    Member SureShot's Avatar
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    Thanks for the explanation Bob.

    So the same theory applies to rifled and smooth bored barrels right then? I assume this theory would apply to airguns and firearms too wouldn't?

    Just when would you need to have your barrel recrowned? If you think it was damaged in some way? How would you know? Poor accuracy?
    I know, lots of questions Eh?
    Ooops, another question.....
    Benjamin NP Trail (0.22)
    Stoeger X5 (0.177)
    SIG Sauer X-Five Open (0.177)
    H&K MP5-PDW (0.177)
    Crosman 3576 (0.177)
    Crosman 1377 (0.177)
    Elite II (0.177)
    Colt Defender (0.177)
    Colt Combat Special (0.177)

  4. #4
    Senior Member SeanMP's Avatar
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    All good questions though

    Yes every gun smooth or rifled is affected by the crown.

    Because I come from a benchrest and fullbore background crowning is meat and potatoes...you wouldn't even consider not doing it.

    Realistically speaking.
    Any older powderburner should be crowned because of muzzle erosion
    New production air rifles will always benefit from a crowning because of the process they use.
    If your modding or doing anything to improve performance the crown should be first thing on the list.

    A guy by the name of Harry Pope was so convinced that the cause of inaccuracy was the instant that the bullet parted from the muzzle that he developed entirely new protocols.Known today as The Pope Method. He created a means by which he could machine the crown absolutely square to the line of the bore and machined the end of his bullets flat and developed a means by which to load the bullets from the muzzle so that the rifling smears didn't affect the square edge on the base of the bullet. In 1883 he shot a 25 shot record that hasn't been beaten to this day.

    Lots of people will have lots of varying views on the subject of crowns. None of these people have 130 year old records to back up their bull$h!t
    Sean

  5. #5
    Administrator AirGunEric's Avatar
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    Oh sure, go and pull Mr. Pope outta there and bring up his 130-year-old record. Doesn't leave alot of room for discussion, does it?

    hee hee



    Mind you, Mr. Pope wasn't just about the crown, he fiddled with everything barrel-related- so his long-standing record is likely attributable to a bit more than simply the crown- but the theory should still hold true. He was also apparently a crack-shot, so his own shooting skill is also going to be part of the explanation.

    Interesting story, Mr. Pope was anyways, here's an interesting article: http://riflemansjournal.blogspot.ca/...arry-pope.html
    I'd say I care- but I'd probably be lying...


  6. #6
    Member SureShot's Avatar
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    And from Larry Potterfield, CEO and Founder of MidwayUSA comes a video;
    Benjamin NP Trail (0.22)
    Stoeger X5 (0.177)
    SIG Sauer X-Five Open (0.177)
    H&K MP5-PDW (0.177)
    Crosman 3576 (0.177)
    Crosman 1377 (0.177)
    Elite II (0.177)
    Colt Defender (0.177)
    Colt Combat Special (0.177)

  7. #7
    Member DocGadget's Avatar
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    Quote Originally Posted by AirGunEric View Post
    Interesting story, Mr. Pope was anyways, here's an interesting article: http://riflemansjournal.blogspot.ca/...arry-pope.html
    Quite well written and very interesting, I'm gonna keep and share that story.

    Thanks Eric

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