RepackboxInline FabricationLee PrecisionRotoMetals2
WidenersTitan ReloadingADvertise here

Results 1 to 6 of 6

Thread: 40 cal barrel best twist rate BPCR

  1. #1
    Boolit Mold
    Join Date
    May 2016
    Location
    Missouri
    Posts
    18

    40 cal barrel best twist rate BPCR

    Looking at Green Mountain barrel. They have both 14.5 and 16 twist. I will be using grease groove cast of about 400 grains. Is the 14.5 to fast? lyman Snover is my go to. 40-90 Sharps Necked.

  2. #2
    Boolit Master
    Join Date
    May 2012
    Location
    Outside Rolla, Missouri
    Posts
    1,025
    I don't have any experience with the faster twist. I do know that if the red gods smile, the atmospherics are right and I'm having one of those rare excellent days, my 40-70 Shiloh Sharps has held MOA out to 600 yards with a 410 gr. bullet. I'm just about positive it is a 1- 16 twist. Deducing from that, 1-16 is evidently plenty. I'm interested to see what others with more experience have to say.
    "In general, the art of government is to take as much money as possible from one class of citizens and give it to another class of citizens" Voltaire'

    The common virtue of capitalism is the sharing of equal opportunity. The common vice of socialism is the equal sharing of misery

    NRA Benefactor 2008

  3. #3
    Boolit Master
    Join Date
    Dec 2008
    Posts
    1,699
    The 1:14.5 is definitely not too fast. I have Shiloh Sharps rifles in 1:16 and 1:14 twist. They are both very accurate. I've shot the 1:16 twist rifle more than the 1:14 twist one, but I can say that they both shoot the Saeco #740 and the BACO 409400M4 bullets very well to 600 yards.

    If I were to order a new rifle it'd be with the faster twist as it has the ability to stabilize a longer bullet and hasn't seemed to hurt accuracy with shorter bullets. But either one will be good.

    Chris.

  4. #4
    Boolit Master
    Join Date
    Jun 2008
    Posts
    1,516
    Quote Originally Posted by beshears View Post
    Looking at Green Mountain barrel. They have both 14.5 and 16 twist. I will be using grease groove cast of about 400 grains. Is the 14.5 to fast? lyman Snover is my go to. 40-90 Sharps Necked.

    NO, it is not. It is perfect.

  5. #5
    Boolit Master



    Boz330's Avatar
    Join Date
    Jul 2006
    Location
    Central Kentucky
    Posts
    3,852
    I have had several 40-65 with 16 twist barrels and they work fine for 400gr bullets. I don't have any experience with a 14.5 but if you want to go heavier it should help. From your post it isn't exactly clear to me whether you are talking the 40-90 or a different 40. I have a 40-50 and it is hard to get the velocity from that short case for a 400gr boolit, theoretically a 14.5 would help.

    Bob
    GUNFIRE! The sound of Freedom!

  6. #6
    Boolit Master Lead pot's Avatar
    Join Date
    Jan 2006
    Location
    In a State that is #1 with people migrating out.
    Posts
    3,004
    I have two .16 ROT .40's one .40-70 and a .40-65 and one 14 ROT .40-65 and the 14 is outperforming the 16's with the same bullets from 1.4" too 1.5" long.

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