Lee PrecisionRepackboxWidenersInline Fabrication
MidSouth Shooters SupplyTitan ReloadingRotoMetals2

Donate Now Goal amount for this year: 6000 USD, Received: 5505 USD (92%)
Our Annual server fund drive is going on now! This donation drive helps fund Cast Boolits for an entire year, and helps support our 2nd amendment rights! You can donate by Paypal by clicking the DONATE button. Or by Cash / Check / MO to the address below:

Willy Snyder
PO Box 2732
Pocatello, ID 83206
****Due to overwhelming e-mails, I will be very slow in updating this list. Please bear with me!****


Results 1 to 3 of 3

Thread: Barrel twist

  1. #1
    Boolit Master



    Join Date
    Feb 2018
    Posts
    1,023

    Barrel twist

    Is there any kind of formula for calculating the best twist rate? Caliber, boolit weight, load, ft/sec, barrel length? Or is it just what has been known to preform well?
    Thanks

  2. #2
    Boolit Grand Master



    M-Tecs's Avatar
    Join Date
    Apr 2008
    Location
    Minnesota
    Posts
    5,364
    2nd Amendment of the U.S. Constitution. - "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."

  3. #3
    Boolit Bub bigbore52's Avatar
    Join Date
    Feb 2015
    Location
    Australia
    Posts
    58
    Greg,

    try Greenhill's ready made formula here :
    https://www.vcalc.com/wiki/AndrewBud...ing+Twist+Rate

    I've not used that link but the following Wiki link has the formula if you want to do it yourself:
    https://en.wikipedia.org/wiki/Alfred_George_Greenhill

    ....interesting most formulae such as Greenhill's rely on a constant and are limited to velocities sub 2400fps - I prefer to use Millers formula (based on Greenhills') that accounts for a greater number of variables including copper jacketed etc...
    His formula called the Miller Twist Rule can be found here

    https://en.wikipedia.org/wiki/Miller_twist_rule

    Hope they help.....

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