280 SHERMAN MAX vs .280 A.I.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by elkaholic, Jun 13, 2011.

  1. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    There have been a few questions on a couple of other threads concerning case capacities of these cartridges so I did a very accurate test today. I took a new .280 A.I. Nosler case and put in an old primer and then weighed the case. I then filled it to the brim with H20 and re-weighed and subracted the difference. The capacity in H20 was 73.4 grains. I then fireformed the same case in my .300 Sherman chamber and necked it back down to .280 and repeated the H20 process. The capacity was exactly 76 grains. This gives a 3.6 grain increase over the A.I. for a gain of 4.7%...........Rich
     
  2. sinarms

    sinarms Well-Known Member

    Messages:
    322
    Joined:
    Oct 24, 2010
    Rich, I don't know what a Sherman Max is yet but I think you added wrong or put the wrong numbers down. It should be a 2.6gr difference by your numbers. What is the base cartridge for the Sherman Max?
     

  3. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,311
    Joined:
    Jul 29, 2004
    Hello Rich.
    I can't find the reamer dimensions on the Sherman so the question is , Can you fire form a 280 rem
    to the Sherman? Just like the 280 AI.

    J E CUSTOM
     
  4. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    Hi Jerry. Good to hear from you. You can but not as simple as chambering the .280 and firing as in the A.I. If I were going to use the std. .280 case, I would first neck up to .308 and then back down to .284 leaving a false shoulder to headspace against. My case measures 2.150" body length to shoulder and my .300 is 2.223 to the neck junction so a .280 would be about 2.237" give or take a couple thou to the neck. Diameter at the body/shoulder junction is .460". You can use my reamer:D....Rich
     
  5. bigngreen

    bigngreen Well-Known Member

    Messages:
    5,840
    Joined:
    Nov 24, 2008
    What kinda numbers do you get with bullets like the 168 or 180 Berger, my dad is putting together a 6.5 Sherman soon and I'm really looking forward to seeing what it will do, if it performs like it looks the speed goats better stay waaaayyy out of range gun)
     
  6. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    Hi Bign'.......I had no idea he was your dad! Ya, that 6.5 will definitely outrun a speedgoat:D I don't have a .280 put together yet but a guy in Lewistown is building one this summer so should have some real data before too long. My guess is that 3150' should be possible with a 168 in a 26" tube. The 6.5 will exceed 3200' with a 26' and I get 3100 with 190 SXR's out of my 300 Sherman with a 28". You'd better build a .280 to stay ahead of your dad:D........Rich
     
  7. rogue savage

    rogue savage Active Member

    Messages:
    33
    Joined:
    Jan 19, 2012
    Old thread but my the .280 Sherman has my interest. Has anyone got any actual data from the 168s or 180s?
     
  8. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    The guy from Lewistown had a lot of trouble with his gunsmith and we are going to rebuild it. We did a little work with it before he had it tied up for over a year and the velocities were impressive. It will exceed 3100' with the 168's. We didn't get to try anything heavier before it went back.
    You can count on it outperforming an A.I. for sure!.......Rich
     
  9. lazylabs

    lazylabs Well-Known Member

    Messages:
    870
    Joined:
    Oct 26, 2006
    Have you compared the sherman to the gibbs version?
     
  10. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    I haven't, but the 6.5 Sherman and Gibbs are identical in velocity and case capacity so the 280 should be as well. Where the Sherman has it over the Gibbs is a far better case design. The Sherman has less body taper, a 40 degree shoulder, and a MUCH longer neck which is the best part.......rich
     
  11. Jcub

    Jcub Well-Known Member

    Messages:
    169
    Joined:
    Aug 8, 2013
    I have a SAAMI .280 AI, could you post a picture of 1 next to your Sherman Max?
     
  12. elkaholic

    elkaholic Well-Known Member

    Messages:
    5,353
    Joined:
    Dec 4, 2008
    I don't know if I have any A.I. brass but will post if I can find one. It looks very similar to the A.I. but has less body taper and the body is longer.....Rich
     
  13. bigngreen

    bigngreen Well-Known Member

    Messages:
    5,840
    Joined:
    Nov 24, 2008
    I think my dad has some 280 AI factory brass that he was going to form some Sherman cases from, I could see if he could put them beside a 6.5 Sherman case and get a picture.
     
  14. MudRunner2005

    MudRunner2005 Well-Known Member

    Messages:
    10,086
    Joined:
    Oct 13, 2008
    Can you use .280 AI Nosler brass for the .300 Sherman?