Titan ReloadingRotoMetals2Lee PrecisionMidSouth Shooters Supply
ADvertise hereInline FabricationGraf & SonsStainLess Steel Media

Page 2 of 2 FirstFirst 12
Results 21 to 28 of 28

Thread: Bought my first micrometer

  1. #21
    Boolit Master

    Join Date
    Mar 2005
    Location
    Bloomfield, Nebraska
    Posts
    5,224
    Uh No a 308 bullet can measure from 307 to 308.5 depending on manufacture. If you read Water's Pet Loads he give the true diameters to all the bullets he loads and most are not to exact spec. A gauge block would be best but quality 1-2-3 will get you close. No sense buying a mike if you don't verify it you just a soon use a set of dial callipers.

  2. #22
    Boolit Master


    HangFireW8's Avatar
    Join Date
    Dec 2008
    Location
    Central Maryland
    Posts
    2,316
    Hornady 44bullets run 0.430" not 0.429"; cheap bulk factory .30 bullets can often be between .307 and .308; Sierra makes the most affordable 30's that come in right at
    0.308".
    I give loading advice based on my actual results in factory rifles with standard chambers, twist rates and basic accurizing.
    My goals for using cast boolits are lots of good, cheap, and reasonably accurate shooting, while avoiding overly tedious loading processes.
    The BHN Deformation Formula, and why I don't use it.
    How to find and fix sizing die eccentricity problems.
    Do you trust your casting thermometer?
    A few musings.

  3. #23
    Boolit Master

    Join Date
    Mar 2013
    Location
    Northwest Ohio
    Posts
    8,514
    A few pin gages, gage blocks or even dowel pins will work. On a zero -1" a pack of cigarette papers close lightly on a paper and slide out a couple times this will clean the faces of grit and grime. The lightly close to your "feel" and check zero. Bullets can and do vary as to dia. Lapua made some 30 cal 170 grn rebated boat tails that were .309 and labeled as such. A 1/8" 3/16" 1/4" 5/16" up thru 1/2" by 1/16" increments wouldn't be very expensive from a local machine shop. Another way is to get together with 4-6 others and their 0-1" mikes and measure items then average the results this will give a very accurate idea of the items size. A feeler gage can be used for thinner small increments to check the mike.

  4. #24
    Boolit Master
    smokeywolf's Avatar
    Join Date
    Jan 2011
    Location
    Too far west of where I should be.
    Posts
    3,383
    Mike standards can be had at pretty reasonable prices on "that auction site". country gent, as usual, mentioned something very useful. Gage pins and even dowel pins can get you dang close or at least in the ball park. Dowel pins will typically run between on-size and 50 millionths fat.

    Because I have a number of machinist's chests, rollaways and service kits, I have not always had my mike standards or Jo-blocks with me on a particular job on a particular day. I have, a time or two, used precision pin gages, reamer-blanks, dowel pins or even end mill shanks to check my mikes.
    A well regulated militia, being necessary to the security of a free State, the right of the People to keep and bear arms *shall not be infringed*.

    "The greatest danger to American freedom is a government that ignores the Constitution."
    - Thomas Jefferson

    "While the people have property, arms in their hands, and only a spark of noble spirit, the most corrupt Congress must be mad to form any project of tyranny."
    - Rev. Nicholas Collin, Fayetteville Gazette (N.C.), October 12, 1789

  5. #25
    Boolit Master 15meter's Avatar
    Join Date
    Feb 2017
    Location
    SE Michigan
    Posts
    438
    Quote Originally Posted by fast ronnie View Post
    The tenths vernier will be on the back side of the barrel. Not all of Starret's mic's have the tenths graduation on them.
    Does the mic have the carbide faces? A lot of them don't have that either, but if it does, it is a nice bonus. You can tell by looking at the tip of the spindle.
    Pretty unlikely it has carbide faces, not sure when Starrett started using carbide faces as an option but I know it was way past the 1920's.

    Still a nice looking vintage mic.

  6. #26
    Moderator



    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    10,340
    Quote Originally Posted by KCSO View Post
    Uh No a 308 bullet can measure from 307 to 308.5 depending on manufacture. If you read Water's Pet Loads he give the true diameters to all the bullets he loads and most are not to exact spec. A gauge block would be best but quality 1-2-3 will get you close. No sense buying a mike if you don't verify it you just a soon use a set of dial callipers.
    Quote Originally Posted by HangFireW8 View Post
    Hornady 44bullets run 0.430" not 0.429"; cheap bulk factory .30 bullets can often be between .307 and .308; Sierra makes the most affordable 30's that come in right at
    0.308"
    .
    Wow, I must be buying the right brands of 30 cal bullets I've never seen a .308 bullet THAT much over/under .308
    But I don't doubt you two have...So, I guess I will no longer suggest using J-words for standards.


    Yes, I agree a gauge block (Standard) is best.

  7. #27
    Boolit Master

    Join Date
    Mar 2013
    Location
    Northwest Ohio
    Posts
    8,514
    With the dowel pins a 1" length or slightly longer gives enough to hold on to and measure easily. another trick is to coat 1/2" of one end in epoxy or a rubber material, even tygon or rubber tubing can be cut and pressed on this gives a nice "grip" to hold with, makes you measure the same end every time, and insulates the pin from oils acids in your skin along with body heat.
    Starret and federal had digital mikes out for many years but they weren't electric but were mechanicals. three wheels were in the frame and geared to the thimble. Federal also had an Indicating mike that had a indicator tied to the anvil these could be set to a dimension and variations read on the indicator.
    I have mostly browne and Sharp measuring tools. Michrometers are from 0-6" carbide faces slant lines and friction thimbles. But also have some starret mitoyo and others. My Mitoyo mikes are digital and read to 50 millionths (.00005) of an inch 0-1 and 1-2. On mikes unless used in a production line environment most will be good thru 3-4 owners LOL. My complaint with the electric digitals is it seems the batterys are always dying

  8. #28
    Boolit Master 15meter's Avatar
    Join Date
    Feb 2017
    Location
    SE Michigan
    Posts
    438
    Quote Originally Posted by country gent View Post
    With the dowel pins a 1" length or slightly longer gives enough to hold on to and measure easily. another trick is to coat 1/2" of one end in epoxy or a rubber material, even tygon or rubber tubing can be cut and pressed on this gives a nice "grip" to hold with, makes you measure the same end every time, and insulates the pin from oils acids in your skin along with body heat.
    Starret and federal had digital mikes out for many years but they weren't electric but were mechanicals. three wheels were in the frame and geared to the thimble. Federal also had an Indicating mike that had a indicator tied to the anvil these could be set to a dimension and variations read on the indicator.
    I have mostly browne and Sharp measuring tools. Michrometers are from 0-6" carbide faces slant lines and friction thimbles. But also have some starret mitoyo and others. My Mitoyo mikes are digital and read to 50 millionths (.00005) of an inch 0-1 and 1-2. On mikes unless used in a production line environment most will be good thru 3-4 owners LOL. My complaint with the electric digitals is it seems the batterys are always dying
    To differentiate between the electronic and the mechanical Mike's the purely mechanical ones were usually called digit mikes. The electronic called digital. Mitutoyo was the best on battery life hands down. Starrett went through several generations of electronics before they started getting battery life to an acceptable level.

Page 2 of 2 FirstFirst 12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check