Load DataRepackboxWidenersSnyders Jerky
RotoMetals2Titan ReloadingMidSouth Shooters SupplyLee Precision
Inline Fabrication Reloading Everything
Results 1 to 9 of 9

Thread: Sight help please

  1. #1
    Boolit Master
    Lefty SRH's Avatar
    Join Date
    May 2011
    Location
    Athens, AL
    Posts
    2,172

    Sight help please

    I recently mounted a Lyman 66A receiver sight on my M94 30-30. I using the factory bead front sight thats either .310” or .315” (bottom of dovetail to top of bead) tall. I plan to replace the front with a Sourdough partridge but want a little shorter front in order to lower the rear. The rear is kinda high right now. The gap from the top of bolt to the underside of the windage bar is .137”
    If I use a .260” tall front thats a difference of .050” from the factory (keeping it simple). Do I just adjust the lower .050” to theoretically keep the same zero I have now?

    If Im wrong on this, what height front do I need to lower the rear about .050”-.060”?
    Last edited by Lefty SRH; 01-14-2020 at 09:24 PM.
    "In GOD We Trust"

  2. #2
    Boolit Master 1006's Avatar
    Join Date
    Apr 2013
    Location
    South of Atlanta, GA
    Posts
    542
    I think you just need to go down the same amount on each sight.

  3. #3
    Boolit Grand Master pietro's Avatar
    Join Date
    Mar 2008
    Location
    New England
    Posts
    5,263
    .

    If you lower the receiver peep sight as low as you want it, then shoot it at 100yds and measure how low it shoots, you can calculate the proper height front sight needed.

    After shooting:

    1.Measure your Sight Radius.
    2.Multiply your Sight Radius times your Impact Distance (the measurement of the POA to the POI)
    3.Divide your Target Distance in inches

    Last edited by pietro; 01-15-2020 at 03:00 PM.
    Now I lay me down to sleep
    A gun beside me is what I keep
    If I awake, and you're inside
    The coroner's van is your next ride

  4. #4
    Boolit Master
    Join Date
    Jan 2018
    Posts
    2,585
    Quote Originally Posted by pietro View Post
    .

    If you lower the receiver peep sight as low as you want it, then shoot it at 100yds and measure how low it shoots, you can calculate the proper height front sight needed.

    After shooting:

    1.Measure your Sight Radius.
    2.Multiply your Sight Radius times your Impact Distance
    3.Divide your Target Distance in inches

    I've seen this formula before - but just wanted to clarify. For a 15" sight radius at 100 yards that is 2" off the mark, is it:
    15"x100(12"x3')
    _________________
    2"
    ??

    Thank you.

    Sent from my Pixel 3 XL using Tapatalk

  5. #5
    Boolit Buddy
    Join Date
    May 2016
    Location
    Missouri
    Posts
    223
    If you come down the same front and rear zero will remain same. At 100 yds with 15 inch sight radius each .001 difference in front sight will change impact .240 inches at 100 yds. 100 x 36=3600 divided by 15=240 x .001 = .240

  6. #6
    Boolit Master

    Join Date
    Feb 2008
    Location
    Bozoland Mt.
    Posts
    1,698
    If a shorter sight is needed, why not just use a file?
    To lazy to chase arrows.
    Clodhopper

  7. #7
    Boolit Master
    Lefty SRH's Avatar
    Join Date
    May 2011
    Location
    Athens, AL
    Posts
    2,172
    Thanks for the help guys.
    I cant and dont want to use a file. That would mess up pre-64 original parts. The original sight is a bead type. A file would ruin it.
    Sure, you can file down a Sourdough Patridge but then you are reducing the size of the brass insert at the top of the blade.
    Last edited by Lefty SRH; 01-16-2020 at 08:15 AM.
    "In GOD We Trust"

  8. #8
    Boolit Master
    Join Date
    Feb 2011
    Location
    SE Kentucky
    Posts
    1,320
    Confused by the 15" sight radius, would have thought the distance from front sight to rear of a receiver on a M94 would be at least 24".

  9. #9
    Boolit Master
    Lefty SRH's Avatar
    Join Date
    May 2011
    Location
    Athens, AL
    Posts
    2,172
    Its actually 22.5”
    The 15” sounds like it measured to the factory buckhorn.
    "In GOD We Trust"

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