7 dakota improved

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 284stak, Feb 14, 2010.

  1. 284stak

    284stak Well-Known Member

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    Trying to decide to rebarrel my 7-330 Dakota to either a 7Dakota or improving it. Does anyone have any experience with an improved 7 Dakota ---- if so, what degree of improvement could I expect over a 7Dakota. I don't mind purchasing a custom reamer - any ideas are welcome. I already have the dakota bolt face and like the efficiency/length of all the Dakota cases, so want to stay with the 7Dakota or an improved version.
     
  2. Kiwi Nate

    Kiwi Nate Well-Known Member

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    The main advantage of improvement would be case life, less trimming, very positive head spacing etc. As far as velocity gains go, any step up in velocity from your current case capacity, will come at the price of severly reduced throat life. Severe erosion will destroy accuracy anywhere between 150 and 600 rounds. If the latter is your goal, It would be better to put the money for a custom reamer towards a Kestrel wind meter to optimize what you already have, after all, wind is far more the enemy to LR hunting than bullet drop.
     

  3. MontanaRifleman

    MontanaRifleman Well-Known Member

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    The Dakota case already has fairly striaght wall and not much room to push them out any farther. The walls are already about the same as an Ackley. The shoulder are 30* and could get pushed to 40*, but I dont think pushing the shoulders to 40* would gain a whole lot and IMO wouldn't be worth the effort. Load some RL17 in it and you might get another 100 fps without having to buy reamers and dies and fireforming.

    -Mark
     
  4. BountyHunter

    BountyHunter Writers Guild

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    +1 on what Mark said.

    Reamer and no go guages $200
    Barrel $300
    chambering $200
    Custom dies- $200-400

    For 100 fps?

    BH
     
  5. 284stak

    284stak Well-Known Member

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    Points taken - sounds like the plain 7 dakota is the way to go. Thanks guys.
     
  6. 7mmRHB

    7mmRHB Well-Known Member

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    The 7mm Dakota case is a bit smaller in capacity than the standard 300 or 330 Dakota. About 5 or 6 grains I believe. The 7- 330 case mentioned is an Imp. 40* called the 284 STAK , same name as the poster of this thread, and holds about 9 or 10 grains more than the standard 7mm Dakota, so there is quite a difference in capacity.

    The 7mm Dakota is a good round and will shoot the 180 VLDs at around 3000fps with out being IMP. ---- RHB
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    When I said that blowing out the Dakota shoulder wouldn't porvide gain a whole lot more, I was assuming he was goung back to his 7-330 Dakota. I agree that there is a significant difference between the standard 7 Dakota and the blown out 330. In anycase, if he was just looking at blowing out the 7, he would gain much. If he still has the 7-330 reamer and dies, I would just go with that if it were me. JMO.

    If I wanted to do a 7 Dakota variation with or without fire forming brass, i would do it off the 300 which has a very slightly longer case at the shoulder and oeverall and doesn't need to be necked down as far, and the shoulder is 32* vs 30* The shoulder If I was getting reamer and dies made I would probably go ahead and do a 35-40* shoulder.

    -Mark
     
  8. 7mmRHB

    7mmRHB Well-Known Member

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    Montana, the reason the 330 was used instead of the 300 was that they ( the guys building the 284 STAK ) found out the brass was much better quality on the 330 brass. Dakota has been upgrading their brass and as of a few years ago when the 284 STAK was built the 300 brass was still poor quality. It may be all the same by now and the 300 brass would obviously make the job much easier to do. --- RHB
     
  9. 284stak

    284stak Well-Known Member

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    My plan is to do away with the STAK - just to many steps in the brass forming for me and we have never been able to achieve the velocities we hoped for without ruining our brass in a few firings.
    My original question pertained only to the 7 Dakota - seems the way to go for me.