Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Measuring to Ogive

  1. #1

    Measuring to Ogive

    Hopefully this is a simple one - I have some load data which gives a measurement to the ogive. I am looking to load some heavier and longer match bullets to the usual soft points and am assuming my measurement to the ogive should remain constant even though the cartridge OAL then exceeds that in the manual. Can anyone provide confirmation that this is ok.

  2. #2
    Nope. Different bullets will have different ogival form and a different measurement. Where are you getting that load data from? I'm curious. It's a fairly non-standard bit of data to hand out. From a private individual?~Muir
    Last edited by Muir; 01-01-2013 at 22:44.

  3. #3
    If this is printed data I am also interested.

    To measure the difference on the bullets you will need a set of calipers and an overall length guage and bullet comparator with caliber specific inserts. This isn't as complicated as it sounds.

  4. #4
    Quote Originally Posted by Muir View Post
    Nope. Different bullets will have different ogival form and a different measurement. Where are you getting that load data from? I'm curious. It's a fairly non-standard bit of data to hand out. From a private individual?~Muir
    Muir Im not looking to pick an argument here, but.. Whilst I understand that different bullets have different profiles etc. Surley for an AOL they will be the same? Albeit they mey protude further into the barrell...


    Nutty

  5. #5
    Quote Originally Posted by biffa View Post
    Hopefully this is a simple one - I have some load data which gives a measurement to the ogive. I am looking to load some heavier and longer match bullets to the usual soft points and am assuming my measurement to the ogive should remain constant even though the cartridge OAL then exceeds that in the manual. Can anyone provide confirmation that this is ok.
    My thoughts are yes the AOL will be the same but the bullet will protude into the barrell further.

    Nutty

  6. #6
    Nope the Ogive will be different on different bullet shapes, so you need a dimension to ogive for each different bullet.
    It's not easy for me (of limited experience) to explain, but I shall try.........
    The calibre specific insert is not calibre size, it is smaller and does not measure the true ogive, but a smaller than bore portion of the bullet.
    That specific dimension it measures will then move in relation to to the true ogive dependant on the taper of the bullet.
    Here are a list of the actual inserts for a few different calibres, these are Hornady (stony point) inserts measured using a vernier.
    Calibre Actual
    .240" .232"
    .220" .213"
    .30" .297"

    So from that you can see the only one that would be anything like close to true reading would be the .30 cal one.
    To put it in engineering terms, it is not a device for measuring anything, it is only a comparator, it accurately compares two identical items, and that is all.

    Neil.

  7. #7
    I agree. Ogives are different between makes and styles. A Hornady and a Sierra, f'rinstance. Any ogival measurement from the face of the cartridge head would result in a different OAL with each bullet. I was thinking the OP was asking if the measurement to the ogive on one would be the same as a different bullet giving the same OAL. Does that make sense?? (I'm doubting myself!)

    With all this emphasis on "distance to the lands" these days, it is odd that measurement to the ogive would hold any water as the relationship between one rifle's chamber and a different rifle's chamber is bound to be different. It is though, when referenced to a specific bullet, a better measurement than "distance to the lands" or Over All Length. More akin to Seating Depth, which is my favorite reference for length -regardless of the bullet.~Muir

  8. #8
    Thanks to all for your replies. I suppose I was thinking that it was only the length above of the ogive (not sure of the terminology so I'm meaning ogive to tip) that would be different for the longer bullets but, as posted, of course the bullet length below the ogive could also be longer. To my mind if I was doing what I'd originally planned which was to keep the same cartridge base to ogive measurement then I may (or probably it would seem) have both a deeper seated bullet and a longer OAL. The load data was from Mike Norris for a 139 gn Hornady soft point and I was going to load some 168gn Bergers for some paper punching. This is for a 7mm-08 which Mike has made for me so I know he has worked up the hunting load carefully and I was originally thinking I would replicate these with the longer match bullet.

    I'm now thinking I should just keep the OAL at the standard 2.8" for starting with.

  9. #9
    Surely if you have a comparator to measure head to ogive why don't you use or get a modified case. You can then find how far off the lands you custom ammo from Mike is and possibly replicate this with the match stuff. However I would suspect you may have to seat it further into the case if the berger is a boat tail.

  10. #10
    I don't have whatever a comparator is...

Similar Threads

  1. CWD measuring
    By wildfowler.250 in forum Articles & Write Ups
    Replies: 1
    Last Post: 04-11-2012, 09:18
  2. worth measuring
    By PKL in forum Deer Stalking General
    Replies: 31
    Last Post: 10-07-2012, 07:23
  3. Measuring Antlers
    By Tim.243 in forum Deer Stalking General
    Replies: 4
    Last Post: 22-12-2011, 13:46
  4. measuring a head
    By McStalk in forum Deer Stalking General
    Replies: 7
    Last Post: 20-10-2011, 12:26

Posting Permissions

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