6.5-06 A.I. vs 6.5 Sherman

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by elkaholic, Dec 7, 2010.

  1. elkaholic

    elkaholic Well-Known Member

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    I shot a 6.5-06 A.I. for twenty years and loved it so I am in no way knocking this cartridge but rather would like to throw something out there for those of you who have shot out your barrel or might want to improve your performance.
    When I shot my last one out, I decided that since I liked the A.I. so much, why not try to improve on it since I was wildcatting anyway. I always used .270 cases because as most of you know, you will end up with a short neck when fire forming a std. '06 when fire forming to A.I. I didn't like the extremely short neck of the Gibbs case, so in a nutshell, that is how the 6.5 Sherman came about. I started with the .270 case to take advantage of the .046" longer case. (.280 also works). I blew the body taper out more than the A.I., moved the shoulder farther forward, and maintained the 40 degree shoulder. The result was a case that holds 75 grs. of H2O and still has a .300" neck. That is an approximate 5% increase over an A.I. and 11% more than a std. '06. I had a reamer built by Pacific and put a 4 contour, 26", 3 groove, 8 twist, Lilja barrel on a 700 Rem with an H.S. stock. I am getting up to 3200' with 140 Bergers, although that velocity is a little hard on cases. My hunting load is at 3150' with 1/4 minute accuracy and GREAT case life. Recoil is low and results on game are impressive.
    Rechambering an A.I. would be simple as all the Sherman dimensions are larger. IMHO this is the ultimate 6.5 without going to a magnum and then your barrel goes south in a hurry. By the way, I have fired close to 1000 rounds so far with no signs of wear or loss of accuracy. Food for thought:).......Rich
     
  2. hemiscrub

    hemiscrub Active Member

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    Rich,
    I have been kicking around rebarreling my 270 but i wanted to stay with the with the .277 bullet and the case. I have looked into the A.I. for the 270 but it seems like everywhere I read people say the gains are not worth it. Now I have read about your sherman and it has got me thinking. The first thing would be what kinda velocity do you think would be possible if it was pumped up to 270 with 150 grain bullets with at least a 26 inch barrel. What is the process like to form cases? How does the sherman case feed compare to the A.I. cases? Where did you get the headspace gauge? Well thank you in advance.

    will
     

  3. hammertyme

    hammertyme Well-Known Member

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    I duplicated Rocky Gibbs years ago using rimmed RWS cases for the break opens from Thompson Center. Rocky used a 35 degree shoulder.

    The first time out everything went just fine with everything above 30 cal. With the 6.5 and 270 calibers. I could never get case life and I noted something wrong with the angle of the shoulder. I checked the reamer and the shoulder was 40 degrees. SO with not getting the velocity I wanted and 3-4 reloads I wasn't happy so changed one reamer to 30 degrees and the other to 35 degrees and my case life problem was solved.

    The 6.5 X57 mini duplicates the 6.5X284 in all bullet weights. The 6.5 X 280 Rem improved beats the 6.5 X 284 by 200fps in all bullet weights. The RWS cases handle the pressure in the same manner the WSM cases do. The funnel like none restrictive shoulder has allowed me to fill the case and I get some very nice velocities.

    Right now I am running 2900+ from a 19" handgun barrel and 130 Accubonds.

    Neal
     
  4. elkaholic

    elkaholic Well-Known Member

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    Will.....I would expect about the same velocity with a 150 .270 as I am getting with the 140's. Forming cases would be a breeze with a .270, Pretty much chamber and fire with some cream of wheat or a bullet seated into lands. I have a headspace gauge and my reamer would work just fine. I don't have any feeding problems at all with a standard Rem feed rail.......Rich
     
  5. hemiscrub

    hemiscrub Active Member

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    Rich,
    if everything goes right in a cople months i might want to rent your reamer and headspace gauge
     
  6. royinidaho

    royinidaho Writers Guild

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    Rich sent me one of his cases a while back. I have it setting in plain view beside a 270 Win case.

    I get 3190 fps with 140 calls bullets in the 270 Winnie 27" bbl. Rich's case design is screamin' something at me that says way more fps is readily available with no down side that I can see.

    One of these days.......
     
  7. hemiscrub

    hemiscrub Active Member

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    You wouldn't happen to have a picture comparing the two would you?

    will
     
  8. Ridge Runner

    Ridge Runner Well-Known Member

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    here's a pic comparing the 6.5 Gibbs to the 270, basicly the same cartridge as the sherman with 2 exceptions
    gibbs has a 35° shoulder versus the 40° for the sherman, and the sherman has a .308" neck vs. the gibbs at around .277
    [​IMG]
    RR
     
  9. hemiscrub

    hemiscrub Active Member

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    thanks rr that looks pretty impressive
     
  10. elkaholic

    elkaholic Well-Known Member

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    The Sherman also has less body taper than the Gibbs. The advantage to the Sherman case is a better neck with the same case capacity as the Gibbs. If you PM me with your personal e-mail, I can send you a pic......Rich