Measuring

Discussion in 'Reloading' started by tayhot, Jan 21, 2012.

  1. tayhot

    tayhot Well-Known Member

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    Normaly I measure based off over all length from base of cartridge to the tip. I recently bought a hornady gauge that measures odd the ogive. Should I use the latter for more accurate reloading?
     
  2. Mike027

    Mike027 Well-Known Member

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    Im no expert but my understanding is that for accuracy you should measure to the ogive. The length from the base of the cartridge to the tip is more important for fit in the magazine.

    I use a Hornady OAL guage with a Sinclare comparator to give me the length to the bullet ogive touching the lands. I then back it off .10 for my finished length.

    Im sure some of the more experienced folks on the site will chime in and help. Mike
     
  3. SidecarFlip

    SidecarFlip Well-Known Member

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    If the bullet protrudes too far, you'll have trouble closing the bolt.

    In a gas operated (blowback) seni-auto the COAL dimension applies.
     
  4. Mutt

    Mutt Member

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    Both.

    Good answers from Mike and Sidecarflip.

    I feel both are important.
    If you're close to the lands you will need to use your new tool to avoid an issue. Tips can vary your COAL by .015" or more & less in some cases. If you're trying to stay 1-5 thou off (or into, for that matter) you're gonna have a problem.

    ETA: that same variance will throw off how much bullet is seated in the case too, causing higher/lower pressure and erratic, inconsistent chrono numbers, just as the lands will. (thought I should add that....sorry....Carry on!) ;)

    As a matter of consistency I measure off the ogive almost exclusively. When I worry about mag length (where tips are important for reliable functioning) I still use the ogive PLUS a "cushion" for varying tip lengths... also, QuickLOAD requires me to measure to the tip for calculations...but that's a different problem and one I'm trying to resolve.
     
    Last edited: Jan 21, 2012
  5. SidecarFlip

    SidecarFlip Well-Known Member

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    Mutt...

    I'm primarily a gas operated blow back semi auto person. This forum got my interest because I bought that .338 Lapua Savage and it's my only bolt action firearm.

    I have to catch myself all the time. I'm used to having the firearm cycle by itself.......lol

    I've dispelled quite a few naysayers at our club shooting 100 yard centerfire benchrest (target diameter 2.5" and ringed) with my Ruger/Accuracy Systems accurized Mini 14 Target. I'll put it up against any Anschtz target rifle and do it all the time.

    Consequently, I load at the maximum COAL allowed because of the magazine fitment (5 round regulation) and the mechanics of the action. I want to cartridge to seat as close to the lands as possible while still cycling reliabily.

    I load H335 in full resized cases with benchrest CCI primers and 55 grain Hornady FMJBT projectiles seated with a RCBS competition front load bullet seater and no crimp.. Not a lot of pressure, typically 22-23.5 grains, watching very closely case length (elongation) and neck tension.

    100 yards don't sound like a long distance but reduce your target area to 2.5" and further reduce the scoreable area to the innermost bullseye and second ring and then shoot 10 targets on one sheet. It gets very intense. Especially when you have a group of half blind old farts blasting away.....:D

    I use a Leupy 6.5x20x50 AO benchrest with extended turrets and a 1" tube.
     
  6. gunpower

    gunpower Well-Known Member

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    Never mind the old farts, because one day you will be old, and possibly blind youself!!! LOLgun)gun)
     
  7. SidecarFlip

    SidecarFlip Well-Known Member

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    ...I am, plus I'm missing some parts.

    Far as sight is concerned, if it wasn't for modern medical science, I'd be wearing coke bottle glasses. As it is, I've had to progress to digital readouts in lieu of vernier instruments. Can't read the graduations anymore.

    ...and my wife is becomeing more beautiful as she ages.......:D

    Too bad machinist scales don't come in LARGE PRINT like the Readers Digest....