ojive and OAL?????

Discussion in 'Ammunition & Reloading' started by Steelersfan, Mar 29, 2010.

  1. Steelersfan

    Steelersfan New Member

    Hello Reloading folks,

    Reloaded my first 20 rounds of .270 Win. yesterday. I have been reloading for my .38 special and .40 S&W for a while and this was my first attempt at bottle neck cases. The ojive on bullets and using that to determine OAL measurement is new to me.

    I understand that the purpose of a comperator is to measure OAL not from the bullet tip but instead from the ojive, which is a more precise way to measure OAL and determine bullet seating depth keeping the ojive a consistent .02 " away from the lands of the barrel. Is this correct?

    So if I used an OAL gauge in my particular .270 rifle and found the OAL is 3.802 (hornady comparator inculded in this measurement), will the OAL for any bullet I choose be 3.802 with the comparator??

    I understand that depending on bullet the OAL from bullet tip to bottom of case will be different due to differnt types of bullet, but the OAL from the ojive should be consistent no matter what bullet I use??? Is this thinking correct? Or will I need to use an OAL gauge everytime I try a new bullet to determine proper seating depth?

    Thanks folks and I hope these questions make sense.:D
  2. stalkingbear

    stalkingbear Well-Known Member

    Due to the fact that different bullets/different weights have different shapes and ogives you'll need to measure using the comparator for each new bullet you load.

  3. cpttango30

    cpttango30 New Member

    Each different bullet uses a different ogive and each will have it's own measurement.

    WHich is more accurate, measuring off of the ogive is more accurate. You can load different bullet to the same OAL using the comparator. You have to watch that you don/t over or under seat the bullet.
  4. Steelersfan

    Steelersfan New Member

    Okay this is what I figured. If my objective is to keep the ojive of any bullet02" off the lands in this same rifle then all I have to do is make sure I use the comparator. I understand that different bullets are going to measure different from the ojive to the tip but if I want the ojive of any bullet .02" off the lands then I just make sure my OAL measurement is the same from the ojive to the rear of the casing. Which is what I will be doing. Therefore there is really no need to go through the process of using and OAL gauge for this same rifle everytime I switch to a new bullet?? Just checking. I think I might change my online name from Steelersfan to ojive. I like the ring of this new word I have recently learned!