7mm-08 162gr in-flight disintegration

Discussion in 'Vintage Topic Archive (Sept - 2009)' started by Silicon Wolverine, Apr 18, 2008.

  1. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    also posted this over at the reloadbench and havent come up with anything.

    Working up a load for a friends rifle- CVA optima in 7mm-08. 1:9 bergara barrel. loaded xx.x grs of reloader 15 behind a hornady 162 gr BTSP. the bullets naver made it to the 100 yard target. there was several small impacts at about 40 or 50 yards and puff of grey smoke as the bullet flew apart. at xx.x grs everything was fine. Any ideas why this happened?

    SW


    Load data removed by: Ari
     
  2. I think a chronograph would tell you what happened.That puppy was smoking.Or you shot a fly.
     

  3. Ari

    Ari Guest

    I really have no idea. But tell me something, do you have to take precautions not to deform that type of round with the ramrod?
     
  4. Sago

    Sago Member

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    Yeah remember the more powder you put in the chamber the faster the bullet will go. Your bullet also spins faster. The centrifical forces are literally tearing them apart. The bullet has more spin then it can handle. Change out the barrel to one with a lower twist rate or back off on the powder.

    Or change the bullet type heaver bullets can take more RPMs from spinning then light ones in the 30 cal range so I feel safe applying that here. NOTE recalculate the pressures for the heavier round. You don't want to deal with over pressures.
     
  5. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    sago- hornady said this bullet should be good up to 2900 FPS in a 1:9 barrel. im pushing it 2600 tops.

    ari- this is a breechloading centerfire. you dont use a ramrod.

    SW
     
  6. Ari

    Ari Guest

    I was wondering.

    But when I looked the weapon up at google they kept showing me muzzle loaders.
     
  7. A couple things come to mind. First is this a long bullet compared to the lower wt bullets for that cartrigde (I don't have any experiance with this cartridge). If so are you setting it deeper in the case? This along with the carge increase could raise your pressures to the point of damaging the bullet as it travels down the barrel. OR are you making OAL longer, forcing the bullet into the lands before firing, which can also raise pressures and do the same thing.

    My other thought is, did you start with a new container of powder? If so, maybe try a new lot number incase there is a problem with the powder. (a ex co-worker bought a new jug of powder and subsequintly blew up his colt saur rifle (cant remember the caliber) because the powder was not what was marked on the container. Scarred him up pretty bad, and cost the powder company a bit of money.)

    I posted this over on the reloading bench also, not knowing which forum you read most.
     
  8. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    bullet is about the same profile as most for this cal, slightly longer. OAl is custom as this is a single shot rifle, and i load the bullet out to the lands. The powder is a proven container ive used for .308 and .223

    SW
     
  9. It was just a thought. If you come up with an answer let us know, cause I am out of ideas
     
  10. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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  11. Ari

    Ari Guest

    Looks like a bunch of fun
     
  12. Gus

    Gus Member

    A fellow I know purchased a new rifle last fall & had problems when he sighted it in. He discovered that a portion (about 1") of the rifleing was galling out of the barrel. :?: