Gain Twist Rifling

[Two Steps]

Can someone explain to me the advantage of Gain Twist Rifling?
I remember reading about it in something that Walter Cline wrote...but I don't remember the advantage (then again, there's a whole lot I don't remember nowadays).
Thanks,
Al

[Hank in WV]

I don't have any personal experience with it but I know a fella that does gain-twist. He explains that you can use very hot loads without stripping the patch. The ball will start spinning slowly and speed up farther down the barrel.

[Two Steps]

Thanks Hank...that sounds familiar...I think    IIFC, Cline was talking about match rifles, and maybe paper patched bullets.?.
Al

[Gordon H.Kemp]

I think the theory is sound , but to me it would be wasted expense and effort with PRBs. If you were shooting conicals thats a horse of a different color . I feel spinning a PRB at high RPM would actually have a tendancy to create a problem .

[Two Steps]

Yeah Gordy...I think that's what Cline was talking about...conicals.
This whole thing came up because I saw a full stock Hawken over on Track of the Wolf with a gain twist barrel...just got me to thinking (I can do that every now & then...but I ddo get a headache) about it.
Thanks,
Al

[Gordon H.Kemp]

Yeah! , every time I try to reason out a passing thought , it generally goes right on by    
 Its been a longtime since I did much with center fire rifles , but the gain twist was used on several of the early wildcat calibers , 218bee 219zipper 25-06 even the now old 270.  I don"t recall if they ever put the gain twist on a production barrel ?  Some claimed it reduced barrel erosion on the hotter cal,

[Two Steps]

Thanks Gordy...I hope I can find the reference I'm thinking of, later today.  I don't want one...don't need one, I don't shoot hot loads or conicals.  You know how it is when you het a thought or partial memory stuck in your head  
Al

[Gordon H.Kemp]

Two Steps , I"m an expert on the part memory skills  .

[Hank in WV]

I wish mine was that good.

[pathfinder]

Wish what was that good?

[Loyalist Dave]

Guys if one is using conicals, then what is the concern for stripped patches?     So a gain twist allows the ball and patch to overcome inertia at the point of ignition, with only a very slight beginning of the twist, and gradually increases the rate of the twist as the ball is already beginning to torque along an axis, and it is much less stress on the patch to add twist to an already twisting ball, than to do it from the starting point.  The ball is given an optimal twist rate by the time it exits the barrel.  This then in theory gives the ball a stable flight over a longer distance..., increasing the accurate range of the ball.  

Some folks think that it was also done in ML rifles for dangerous big game at standard distances, the velocity of the ball being a good deal higher than in a standard barrel, but soft lead at high velocity deforms so fast on impact that on  DBG animals you actually get less penetration..., and a better chance of the DBG turning on the hunter.  Later when alloy bullets in fixed ammunition were developed, gain twist in some "African" loads was also popular.  When jacketed bullets were invented, the idea pretty much stopped for the copper or nickle could take the torque without rupture,....,  until WWII and Korea, where the idea was again used to provide extra punch in a high vel 20mm Anti-tank gun but it wasn't the spin on the round, but the torque on the gun and the mount that was the problem..., and that last saw use in the US Army in the 1960's

LD

[Captchee]

Guys if one is using conicals, then what is the concern for stripped patches?

  well for one some of the European muzzle loading rifles of the later 19th century used a cloth patched conical . The  Swiss  Stutzer  and German Jeagerguwehree “spelling “
  to name a couple  .

[Gordon H.Kemp]

L.D. very good , very good basic discription of the theroy behind the purpose of the gain twist . However , its my opinion that with reasonable max loadings of the PRB (soft lead) that it takes but a very low rate of spin to stablilize the RB . This , to me , is a theroy best applied to modern CF weapons where HV long conicals with hard alloy coatings need to be spun at high RPM to stablize the projectile at extended ranges as the velosity falls off , or the projectile will tumble and key-hole before it impacts the intended target.  This is one of those theroys that can be discussed for hours  such as the free floating barrel as opposed to a glass bedded barrel .  
        When they first announced the R.E.A.L. bullet , the first thing that came to my mind was someone had stumbled across the successfull use of the pre-engraved rotating bands on the rounds used in the short lived recoiless rifles used with good effect in Korea , and applied it to muzzle loaders . For myself , I"ll stick to the more common slow twist and a patched soft lead round ball.  

[Uncle Russ]

FWIW: I have read that when Sam Colt sold the US Gov't. a phony bill-of-goods regarding the manufacture of the 1861 Colt Rifle, one of his strongest arguments was progressive, or gain twist.

He also claimed his Colt Rifle would be much better manufactured than the current Springfield, yet the current supply level of extra parts for the Springfield would be interchangeable with his new Colt. (You may have to think about that one for a moment.)

He also claimed that the progressive twist barrel was much more accurate than the plain or constant twist because a round ball, or conical, traveling through the bore would meet increased resistance at the point of progressive rifling, thereby creating a longer and more even pressure curve, resulting in greatly improved accuracy.

Samuel Colt was one of this Nation's greatest gun builders.... he was also a pretty good salesman.

Uncle Russ...

[Two Steps]

Well. I Googled Gain Twist Rifling and got more options than I can put here.  A lot of it is about modern rifles (and pistols), but there is info out there about MLs too.  I'll try and grab one of the ML blurbs later and post it here.
Al