General discussion > Black Powder Shooting

Gain Twist Schooling

(1/4) > >>

Pvt.Jack:
Can someone school me on gain twist. I understand what it is and how it works. What I don’t know, is there a certain ratio or percentage of gain per caliber, or something to that effect? Or a certain starting rate based on the ending rate?
Hope this makes sense.

Dphariss:
Gains for round balls and picket bullets can be pretty aggressive. For bullets with long bearing surfaces 1/2” gain has been proven to work well. But these are much faster twists than found in MLs.
IIRC correctly many picket rifles had a starting twist around 48” and an ending twist in the 30s. The faster twist shot better and the slower starting twist helped eliminate blown patches. Picket rifles usually needed pretty large charges of powder to shoot well considerabley more than the RB from the same rifle. Or so I was told and found out in the straight 48 twist 40 cal I was playing around with at one time.

Dan

hanshi:
I still own a .45 gain twist barrel and the accuracy is beyond reproach.  IMHO it would not be such a bad idea for prb rifling to have just a trace of gain anyway.  On most all the barrels available to us it's not needed; but nothing is worse than any amount of slowing toward the muzzle.

Bob Roller:

--- Quote from: hanshi on April 09, 2022, 10:48:44 PM ---I still own a .45 gain twist barrel and the accuracy is beyond reproach.  IMHO it would not be such a bad idea for prb rifling to have just a trace of gain anyway.  On most all the barrels available to us it's not needed; but nothing is worse than any amount of slowing toward the muzzle.

--- End quote ---

Bill Large made a number of gain twist round ball barrels but I can't remember the ratio and I helped make the machines.
After Bill passed away,20 years later Jim McLemore in Hebron,Indiana bought all in Bill's shop except the cobwebs and he
also made round ball barrels that really perform.Harry Pope's muzzle loaders were entirely different and used long bullets and usually started with a 1 in 16 and ended in 15 and 3/4.Pope always said the last inch of any barrel will determine the accuracy and he was right.
Early versions of the German 88MM gun that was such terror had a gain twist and Bill Large and some Army officers checked out one and
Bill told me the first time he heard it go off he knew what was going on with it.Not all 88's had this system,probably because it took longer to make and by that time Russia was a major problem for them.The 88 was originally intended and was used as an anti aircraft gun and after that it appeared on the Panzer 6-1's and 2's better known as the Tiger tank.
Bob Roller

Carl Young:
Hello Jack, if you really want an education on barrels begin by read this: https://www.wolfeoutdoorsports.com/the-story-of-popes-barrels/.

Carl

Navigation

[0] Message Index

[#] Next page