338RUM factory brass weight

Discussion in 'Reloading' started by 86alaskan, Oct 6, 2018.

  1. 86alaskan

    86alaskan Well-Known Member

    Messages:
    825
    Joined:
    Jan 8, 2014
    Can someone that has a piece or two of remington 338RUM brass weigh it for me? I'm working up loads for mine with ADG brass and I ran into pressure over 4gr under the IMR listed max. I'm loading 300gr SMK at 3.75" which is .160 longer than book so that should help lower pressure as well. Trying to figure out how much heavier this brass really is.
     
  2. phorwath

    phorwath Well-Known Member

    Messages:
    6,275
    Joined:
    Apr 4, 2005
    Loading longer with seating depth could actually increase pressure.
     
  3. phorwath

    phorwath Well-Known Member

    Messages:
    6,275
    Joined:
    Apr 4, 2005
    I scrounged around the reloading room and found two R-P cases.
    With no primers, these two empty casings weigh:
    1) 266.5gr
    2) 267.4gr
     
  4. 86alaskan

    86alaskan Well-Known Member

    Messages:
    825
    Joined:
    Jan 8, 2014
    thanks, I'll compare when I get home. that 3.75 load is off the lands, not quite sure how far as I'm just getting started with this one. I'm using IMR 8133 and the max load with shorter COAL is 96, but at 92 I had to tap the bolt open, was definitely sticky.
     
  5. can1010

    can1010 Well-Known Member

    Messages:
    395
    Joined:
    Feb 27, 2012
    my ADG 338 rum brass 259.4 that was a 20 piece avg
     
  6. 86alaskan

    86alaskan Well-Known Member

    Messages:
    825
    Joined:
    Jan 8, 2014
    Measured my brass, came in right at 260 also. Guess I'll just dial back. I hope I don't lose too much speed with a low a charge as I'll have. I'm guessing around 90gr 8133
     
  7. gunaddict

    gunaddict Well-Known Member

    Messages:
    608
    Joined:
    Apr 18, 2010
    I have over 600 NEW, 338 Ultra Mag Remington brass fully prepped and weighed. All new brass has been neck sized, trimmed, chamfer inside and out, and flash holes done. These 338 Ultra Mag brass is from 4 different lots. All brass is sorted within 1 gr. Example: 265.0grs to 265.9grs.
    29rds-262grs
    28rds-263grs
    113rds-265grs
    160rds-266grs
    158rds-267grs
    98rds-268grs
    34rds-269grs
    I hope this helps