Bullet comparators - thoughts and recommendations

Discussion in 'Reloading' started by slymule, Dec 16, 2008.

  1. slymule

    slymule Well-Known Member

    Mar 6, 2003
    I'm thinking I need to pick up a bullet comparator. I'm finding way too much varience in the length of various bullets I'm using. Once I determine what my OAL length needs to be, would just using a bullet comparator get me close enough to maintain a constant seating depth? Or would I need to take it a step further and use something like a Davidson seating depth checker or a Redding Instant Indicator? Main concern is being able to maintain a constant seating depth off the lands. Looking for recommendations from the members as to the quickest and simpliest method that will produce uniform seating depth measurements. Thanks.
    Last edited: Dec 16, 2008
  2. bowhunthard

    bowhunthard Well-Known Member

    Sep 5, 2008
    I recently purchased the Hornady Bullet Comparator, and it is probably one of the simplest and most accurate way to measure your seating depth consistently, as it measures off the ogive of the bullet (not the tip, as there can be "semi-large" differences between the overall length of each individual bullet) therefore, the length measured by the Comparator is shorter than COAL (ie. 2.130" vs. 1.792" in a .222 Rem). You would have to measure the COAL without the tool first tho to make sure they are in spec with length (not really that important unless you are using them in a magazine or hinged floorplate, etc.). If you are using the rifle as a single shot, the Comparator works beautifully with the Hornady O.A.L. Guage, but usually the COAL is over SAAMI specs when done this way.

    Good luck.

    Red Mist. It's an addiction! gun)

  3. eddybo

    eddybo Well-Known Member

    Jan 5, 2007
    I was visiting Don Geraci yesterday and he built an interesting tool for checking bullet length. It is basically a base with a stand that holds a dial indicator at a specific height. He then took barrel stubs that match his barrels and ran the reamers that match his chambers into the stubs. All he does is drop the bullet into the stub point first and run it under his indicator. It basically compares ogive to base measurments, but from the lands. I know he can't compensate for the length changes as his throat erodes but I thought it was a neat idea to have a compararator that matches your chamber exactly. Next time I visit will take to pics because I am not sure I can describe it well enough to illistrate it.
  4. BountyHunter

    BountyHunter Writers Guild

    Jun 13, 2007

    John Buhay in PA has been making them for abvout 5 years and selling them thru RW Hart and David Tubb is selling the Buhay model under his name. You can go to either Tubbs site or RW Hart and see them. by the way, they are the cadillac of ogive checkers.

  5. lever-hed

    lever-hed Well-Known Member

    May 8, 2008
    yep. The bullet comparator works good. Get one, its worth its weight in gold and probly more. The ogive dimension is much more consistant as bullet lengths can vary so much. My Sierra 117-gr SBT loads to 2.716" oal to ogive and is over the oal to tip recommended length, but I don't even look at that dimension as OAL to ogive is the more important dimension, and much more consistent then measuring to bullet tip. :)