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Trim cases before sizing?

litetriggerlitetrigger Member Posts: 320 ✭✭
edited December 2013 in Ask the Experts
Should you trim before or after sizing?


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    BT99BT99 Member Posts: 1,043
    edited November -1
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    charliemeyer007charliemeyer007 Member Posts: 6,579 ✭✭✭
    edited November -1
    For new brass I flash hole de-burr, then a lite inside champher. Provide they fit the gun I load and fire a cast bullet to fire form. Then trim and inside/out champher. Very little Lee lube applied the the inside of the neck via a q-tip first, can help during resizing.
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    tsr1965tsr1965 Member Posts: 8,682 ✭✭
    edited November -1
    This should be in the reloading forum, but I will enlighten you on the whole process.

    First the brass should be sorted by manufacturer.

    Next it should be cleaned...alwaysclean before and after sizing. First cleaning, to remove dirt and debris, so as not to wear, or ruin your sizing die. Second cleaning is to get reloadiing lube off, and primer pockets clean.

    Then is the lube and resizing. I like the Hornady One Shot brand of lube. I have tried other industrial mold release type stuff, and a mold release doesn't mean it is a good lubricant for resizing.

    Then you trim, deburr and chamfer the case mouth. Try to keep the case length to minimal will work better if you crimp.

    Next is the priming. When priming, and every step after that, it is extremely important to make sure you are wearing your PPE(Personal Protective Equipment) glasses, and/or face shield, hearing protection, and a full length industrial type apron. If you have a primer feed, and accidentally set off a primer, when priming a case, you stand a chance of blowing the whole tube or tray.

    Then comes charging the case with propellant.

    Seating a bullet, and crimping are next. Make sure your bullet is seated far enough back, not to engage your lands in your rifling. Also, there are abundant amounts of time where a crimp is not even needed. Some of the more experienced, use a light crimp to get a more consistant powder burn. Instances I don't crimp..for my AR's, for my bolt guns, and for my single shots. Revolvers get a heavy crimp, as do anything, with tubular magazines.

    All of this said, one thing to remember about new brass...unless it is top shelf brass, like Nosler, Lapua, or Norma, contrary to other's popular belief, it does not come ready to load...especially for the high end accuracy crowd. I resize evrey thing, even new brass, to make sure I have consistant neck tension on the bullet. Of course resizing, means trimming, and some even take it a step further by turning the neck for consistant thickness.

    So there you have it. ALWAYS trim AFTER sizing the case.

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    ammo guyammo guy Member Posts: 810 ✭✭✭
    edited November -1
    Trim after in my opinion.
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    AmbroseAmbrose Member Posts: 3,173 ✭✭✭✭
    edited November -1
    Trim after sizing since cases lengthen during the sizing process.
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