Trimming 300 wsm brass

Discussion in 'Reloading' started by K-HILL, Jul 30, 2018.

  1. K-HILL

    K-HILL Well-Known Member

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    Nov 23, 2014
    Resized the brass then measured. Findings were that the brass needed trimmed . Using RCBS trim pro and proper shell holder, so found some of the cases extremely hard to get into shell holder . Never had this problem . Any help would be greatly helpful .
    Thanks
     
  2. LoneTraveler

    LoneTraveler Well-Known Member

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    Feb 7, 2014
    Been there and done that. Glad to help you.
    If you are using a standard H&H Belted case, NO. 4 RCBS shell holder it is not an exact fit for the 300 WSM case. RCBS lists a shell holder for the WSM Series of cases as RCBS Shell holder NO. 43. I had a RCBS No. 4 and started loading 300 WSM with it. Next 100 pack of cases I got would not fit. Got to investigating and ended up ordering a NO. 43, Problem solved. I just went and got my shell holders and measured them. My RCBS No. 4 opening is .468 My RCBS- NO. 43 opening is .480. That .012 difference is the problem.
    Good Luck and happy loading.
     
    sedancowboy likes this.
  3. K-HILL

    K-HILL Well-Known Member

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    Nov 23, 2014
    Unfortunately the problem isn't the shell holder . I am using a #43
     
  4. tailbon3

    tailbon3 Well-Known Member

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    Aug 24, 2009
    I've had that problem too with one specific batch of winchester brass. Somehow the cases were manufactured with rims that were too thick to slide into the shell holder.