284 rebarrel

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Richwv, Feb 9, 2011.

  1. Richwv

    Richwv Member

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    I have an old 300 win mag I want to rebarrel. I am thinking about a 284 Winchester (I like regular cartridges not that popular anymore)and wanted some input on what kind of performance I might beable to get. I am new to this but thought with longer actioni would be able to leave bullets out and not cut into case capacity evenwith longer high BC bullets. Any thoughts?
     
  2. WildRose

    WildRose Well-Known Member

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    My first thought would be to go to either the .264 WM or .260 Rem, or even 6.5x55 due to superior down range ballistics of the 6.5 vs 7mm... .

    If I were going to stick with a 7mm, I'd either go to the 7mm STW(which I absolutely love) or 7mm R mag.
     

  3. Hntbambi

    Hntbambi Well-Known Member

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    That's cool, but you will have to get a new bolt as the 284 Win uses a .470" bolt face compated to the standard belted magnum case head of .540". Maybe you can find someone that will trade you a standard action for a belted mag action. Other than that, you are on the right track. I am also tossing the idea around on what my next build will be. Leaning highly towards a medium length cartridge on a long action to seat long bullets far out, maximizing the powder capacity.
     
  4. Richwv

    Richwv Member

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    I would like to stay with the 7. Will the STW fit a savage 111 300 win mag action. I would really like to go with the 284 anyway just not sure what I could expect extra with a longer action if anything over commercial ballistics?
     
  5. Hntbambi

    Hntbambi Well-Known Member

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    Actually, the heavy 7mm bullets (180+ gr) will give you better downrange numbers than the 6.5mm. The benefit of the 6.5mm is the bullet is lighter (140 gr) so you get less recoil.
     
  6. WildRose

    WildRose Well-Known Member

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    No the 6.5 gives you much higher ballistic coefficients so you have better long range peformance in both accuracy and retained velocity.

    A great example comes from comparing the .260 140 gr to the .300 wm 180gr.

    At a thousand yards using standard loads you have 110 inchess less drop from the .260.

    Pull up a ballistic calculator and compare long range performance between 7mm and 6.5 using standard loads and you will see similar results. The Higher BC of the 6.5 is more stable, and retains velocity better.
     
  7. WildRose

    WildRose Well-Known Member

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    The parent case for the .264 is the .338 wm if I remember right so yes I believe you could build the STW on the same action. You can probably also go with the Remington 7mm ultra mag on that same action.
     
  8. Richwv

    Richwv Member

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    Thanks hntbambi, that is what I was thinking. Heard alot about the 180 Bergers. I beleive The bolt would be an easy change on my savage, can just change bolt head I think. I know some wildcats would get better performance ( I could go 7mm-300) but I like the idea of a 284. I am alright with the factory numbers just wondered if I could improve on that because of the longer action. How do people meshes capacity with water and still measure to a certain length. I don't think I could hold bullet in case and shove it in while fitting it in my calipers?
     
  9. eddybo

    eddybo Well-Known Member

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    I do not have to pull up a ballistic calculator to tell you that there is not 11MOA of difference between a 7mm WSM running a 180 berger and a 6.5WSM running a 140 berger at 1K. There is maybe 4 MOA advantage to the 6.5 and it is starting out probably 300fps faster than the 7mm 180.
     
  10. Hntbambi

    Hntbambi Well-Known Member

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    WildRose,

    Since both the 6.5-284 with the 140 gr bullet, and the .284 Win with a 180 gr bullet can reach 2950 fps with modern powder, the trajectory is very similar out to 1000 yards (<1 MOA delta - 284 shoots 8" less drop and 5" less drift). The benefit is the .284 Win has 40% more energy at 1000 yards.

    6.5mm 140 gr Berger Hunting VLD

    G1 - 0.612
    G7 - 0.313

    7mm 180 gr Berger Hunting VLD

    G1 - 0.659
    G7 - 0.337

    This data was calculated on LoadBase 3.0
     
  11. WildRose

    WildRose Well-Known Member

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    4MOA at 1000yds is a significant difference.

    Like I said, I PERSONALLY shoot a 7mm STW and love it. He asked what he could do with his current action and so that limits him to the large magnums in either 6.5 or 7mm.

    That limits us to 7mm STW, 7mm Ultra, or .264 WM due to the bolt face and action length.

    While for most shooting applications the BC's and potential loads for both the 6.5 and 7mm options available the differences are minimal, the .264 is still the ballistically superior bullett due to it's higher Ballistic coefficient.
     
  12. Richwv

    Richwv Member

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    Thanks everyone this is my first forum and I appreciate all the info.
     
  13. eddybo

    eddybo Well-Known Member

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    Please post a link showing that the 6.5 140 berger has a higher BC than the 180 Berger, I think you are confused.

    BTW the reason for the 4 MOA differntial is that the 6.5 bullet left the muzzle at nearly 300 FPS faster than the 7mm 180. If they had left at the same velocity the 7MM would have had less drop. In a couple hundred more yards the 7mm will have less drop, because of its higher BC. I gave that example because I knew the ballistics off the top of my head because I shoot both.

    BTW I usually build WSMs on long actions. You forgot the lowly 7 Mag. Actually the 7 Mag or 7STW would be his best non-wildcat choice so that he does not have to open the feed rails as he will have to for all the UMs and WSMs. If he wants a wildcat a 7mm/300 Win would be about the best of both worlds.
     
  14. WildRose

    WildRose Well-Known Member

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    No I didn't forget the "lowly 7mm R Mag".

    http://www.longrangehunting.com/forums/f19/284-rebarrel-67853/#post471668

    I shot a 7mm Mag from the age of 14 until I went to the STW about 15 years ago.


    I also entered this thread to share my thoughts in answer to the man's questions, not to get into a pissing contest.

    With that I believe I'm done here.