Results 1 to 5 of 5

Thread: C.O.L. Question

  1. #1

    C.O.L. Question


    I have a couple of questions I'm hoping someone can help me with.

    1. Can I use the same reloading data for Hornady 87 gr HPBT for a Hornady 87 gr Soft Point?

    2. I have set up my bullet seating die, and its spot on for 68mm, which is the C.O.L is for the 243 87 gr Hornady soft point I'm using. But, because the points are soft and have been jangling around in a box, my various dummy rounds were varying around the 68mm mark rather than being spot on.

    So how far can I allow them to deviate?

    Is the COL a maximum, mean or minimum value?


  2. #2
    Distinguished Member tartinjock's Avatar
    Join Date
    Dec 2007
    Nairn, Inverness-shire
    Richard Lee 2nd Edition does not specify differences in Bullet makeup, it just lists bullet weight.

    C.O.L can I believe be varied according to chamber/rifleing etc, I assume that's just given as the measurement given on that complete round at test. Therefor, if you have your equipment setup to match their setup, you should get the same readings.

    Speer Reloading gives a very definative statement about C.O.L.
    But it also states that this is used for their load tables.

    Hope that helps.

    I'm sure,if that's wrong someone will let you and me know.


  3. #3
    Different bullets have a different ogive or profile and therefore seating length can vary in different rifles before they touch the rifling.
    An overly long seated bullet may not fit into a magazine.
    Personally I do not worry too much about seating length as I always try to load for the smallest group and never worry too much about velocity or seating depth.
    What may be a one-holer in Toms rifle may be rubbish in Harrys.


  4. #4
    COL can be divided into two groups max and min. The main difference being that over the max and it will quite often not fit the magazine or if too long jam into the lands, and going under the min is if I remember correctly detrimental to pressure.

    What the manufacturers do when specifying COL be it min or max, they usually specify which, is to place it in the SAAMI specs, . Which basically means it will fit the chamber of any gun of that calibre. However your chamber will be different to any other chamber so what you do as a reloader is to tune the round to fit your rifle. The ogive, the front profile of the head will be different for every type, therefore you need to find the maximum length for your chamber and work from that.

    I'm with Stag on this if it works in your particular rifle that is good enough, providing it is done safely.

    If you want a complete guide, VV Guide


  5. #5


    when i started reloading i got really tense over the length of my rounds. I smoked bulletsand got them all really close to it. i shot some pretty good groups. then one day i was out stalking with a mate of mine with my .30-06 loaded with 150 gr gamekings (spbt) i went to remove a live round from the chamber and the bullet stayed on the lands and the case came away leaving the action full of powder. It made me look bloody stupid.

    the 150 gr gameking is a relatively short bullet and the .30-06 is made for heavier bullets up to 220gr round noses. so not much of the bullet shank was in the neck, the round was too long, there was not enough neck tension. so i measured a federal 150 gr round i had laying about. then i ran all of my rounds back though the dies, because the 150gr spitzers have a steeper ogive i turned the die back half a turn or so more and i ended up with the rounds being notably shorter. .... there was no discernable difference in accuracy at 100yards. i then did the same with the .243 i took them back to the crimping groove.

    this made them more accurate.

    don't get too tied up with col. for our purposes saami length accuracy is fine. you need rounds that won't pull apart, won't bend in ytour pocket and will reliably feed from your magazine. i suspect if you were bench rest shooting things would be different


Similar Threads

  1. Different 6.5 question
    By Dan Newcombe in forum Rifles & Calibres
    Replies: 54
    Last Post: 05-03-2010, 15:18
  2. Question re Variation
    By W16OEN in forum Legal Issues
    Replies: 6
    Last Post: 14-01-2009, 23:12
  3. DSC1 Question
    By Stringer in forum Deer Stalking General
    Replies: 3
    Last Post: 12-01-2009, 13:23
  4. Serious Question ?
    By Grantoliver in forum Deer Stalking General
    Replies: 3
    Last Post: 30-09-2008, 06:20
  5. A Question for the modertors
    By Sam in forum Deer Stalking General
    Replies: 4
    Last Post: 14-09-2008, 23:16

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts