6.5 Sin

Discussion in 'Long Range Hunting & Shooting' started by sinarms, Mar 19, 2012.

  1. sinarms

    sinarms Well-Known Member

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    Been swamped for the past months, I have my chamber reamer and HS gauges for the 6.5 Sin, still waiting on the die reamer. Expect more to come shortly.
     
  2. sambo3006

    sambo3006 Well-Known Member

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    Sweet! It ought to be a pretty impressive round.
     

  3. sdhunterman

    sdhunterman Active Member

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    I'm looking forward to following the progress on this.
     
  4. jlamb

    jlamb Well-Known Member

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    What is the 6.5 Sin based on?
     
  5. gunwalker

    gunwalker Well-Known Member

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    "Devin based it off a shortened RUM case however I am using 330 Dakota brass made by Norma" Long Time Long Ranger

    I pulled this from one of the other threads and the 6.5 is just a necked down version from what I understand after following the other threads.
     
  6. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    Congratulations Devin, That is going to be a sweet 6.5. The 330 dakota brass will work guys in the 338 SIN if you don't mind a short neck. It was just very easy for me to neck the dakota and fireform since I didn't have a die to form the shortenned 338 RUM case. I think the 7mm Dakota is the same as the 338 Dakota and would work for the 6.5 if it is the same case. I would expect near 264 STW velocities with it and right now I am shooting 3800 fps with 123 Amaxes and 3750 fps with 129 sst's in the STW.
     
  7. 7mmRHB

    7mmRHB Well-Known Member

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    The 7mm Dakota is a lot shorter case in the body and overall length, than the 300 and 330 Dakota case. I've designed and built Wildcats on both of the Dakota cases ( 270 AMP 284 STAK ) and a Shortened RUM case( 7mmRHB ). The RUM brass is .545 at the web and the Dakota brass is .542 so they aren't interchangeable unless you don't mind a belly in you're fired rounds?

    It's a lot less work to use the Dakota brass if the neck length is acceptable and the reamer is designed for it. Using short necked brass in a longer necked chamber is not a good thing for best accuracy as it allows the bullet to form into the excess space at the end of the neck under pressure before the bullet starts down the bbl.

    Shortening brass for a wildcat is labor intensive and takes more skill to get good brass after the process !! I'm doing my own 6.5 Wildcat right now that is based on a shortened 6.5 X .284 case and it is always an adventure getting the steps just right. This round is designed to fit a standard short action and still be able to seat a 140 vld in the proper location while getting a boost in performance over the 6.5 x47, 6.5 Creedmore and the 260 Rem. It holds 4 more grains than the 260 even though it is about the same length as the 6.5 Creedmore.

    The riffle is built and broken in so it's time to see what it's capable of. --- RHB
     
  8. liltank

    liltank Well-Known Member

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    Now hold on here.... I thought the SIN was based off the 375 Ruger case???
     
  9. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    Sorry, I meant the 300 would be easier to do the 6.5 so you don't have to go all the way down from 338. The Dakota is a little larger at the base and not smaller than the RUM.

    It is based off the shortenned RUM and not the Ruger.
     
  10. 7mmRHB

    7mmRHB Well-Known Member

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    Dakota brass is .003" smaller at the web. Fact not fiction. That's a significant amount if you are going to use it in a chamber that was intended and designed for RUM based wildcats. --- RHB
     
  11. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

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    7mm, my point is the dakota has a .545" case rim diameter and the RUM a .539 case rim diameter so to use the Dakota brass the bolt face probably will need to be opened up a little. I recomend using the RUM brass when Devin gets dies for it. Because the RUM is slightly larger just in front of the case rim a slight bulge will develop there when using Dakota brass. That plus the short neck is why I do not recomend the dakota brass as a permanent solution. That was and still is my only option for now. I wanted to get all the data I could as quick as I could. The performance is the same with either brass for collecting data. I hope Devin gets some dies out soon to remedy this.
     
  12. sinarms

    sinarms Well-Known Member

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    Here is the reamer print, I am hoping to get one barrel done for it this weekend/early next week

    [​IMG]
     
  13. sinarms

    sinarms Well-Known Member

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    I haven't posted on here for a while but I have done some testing. so far I am getting 36-3700 fps with 140gr bullet and 3550fps with the 160gr Matrix bullet. I will get doing a lot more testing with the 160gr before I go back to the lighter stuff. my original test barrel is a 30", I am also testing a 24" too.
     
  14. calhunter805

    calhunter805 Well-Known Member

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    Any update devin?