High ES--Inconsistent Bullet Speeds

Discussion in 'Reloading Forum (All Calibers)' started by galold, Feb 8, 2007.

  1. galold


    Jan 16, 2007
    I am fairly new to reloading and have a question about cronying handloads. I am very careful and precise with every load. I weigh each powder charge, debur, and use high quality tools. My question is, when I crony each shot is it normal to have allot of variation in the bullet speed. Some shots are within 15 FPS and others vary 140 FPS. If this is not normal what am I doing wrong? I am reloading a 300 ultra mag.

  2. Forum Boss

    Forum Boss Administrator

    Sep 9, 2009
    What dies are you using?

    How much tension on those necks?

    Do you have the expander plug on the decapping rod?

    Are you crushing powder with the base of the bullet?

    Best way I know to reduce ES,assuming you are already weighing each charge) is to get your neck tension more consistent, and often that means reducing tension to around .002".

    I assume you are NOT crimping the necks over the bullets.

    But before you do a lot of things different, borrow a different chronograph. In certain light conditions, a Shooting Chrony will produce results like yours, while an Oehler will not. I've experienced this first-hand.
  3. ronemus

    ronemus Gold $$ Contributor

    Jan 9, 2007
    Primer seating makes a big difference - you want the primer to bottom in the pocket, then have the anvil press firmly on the pellet without breaking it. That requires a lot of feel, and the only tool I've found that provides it is the Sinclair; at $100 each it's rather pricey, but once you try it you'll be hooked.

    You'll probably want to try a variety of primers. I keep a tray of all that I can find on hand, and try them at a middle stage of load development. ES and SD are strongly primer dependent. My .223 loads with RL-15 or N-550 like the WSR, but the .284 with RL-19 likes the 210M.

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