Twist gain?

[Rhinorider]

I was looking at some in stock barrels at Bruno's and I notice there are several that have a tightening twist rate. One in particular is 1 x 8.75 to 8.3..... What is the theory on this, advantages vs disadvantages?

 

[fdshuster]

Actually called "Gain twist". The idea was to start the bullet off slow with the twist increasing gradually as the bullet travels down the barrel. Claimed to cause less stress on the bullet.

They've been on the market for a number of years now, have never heard anything good or bad about them.

A friend has a 6BR with a gain twist & reports that he's seen no difference than a standard, fixed rate twist.

Could it be another example of advertising hype (?), like so many other "new" offerings we've seen? Remember the Remington E-Tronix primers that would make conventional primers obsolete? New powders, new bullet designs, etc. etc.

 

[KevinThomas]

Rhinorider,

They're not exactly new, and have actually been around for well over a hundred years now. The Italian Mannlicher-Carcano service rifles adopted way back in the 1890's used a gain twist, and a much more extreme example of this than the 1x8.7" to 1x8.3" you mentioned. Their's started off damn near straight, and finished with something close to a 1x7" to stabilize the long 162 grain FMJ-RN that wazs then the standard service bullet for the Italian miltary. Seems like the concept gets resurected every decade or so, and then fades back into obscurity . . . for a while.

 

[Doris123]

That's really great!

 

[JDMock]

Gain twist barrels as made by Bartlein have done quite well. Tony Boyer continues to pile up HOF points with his 15-14.25 gain twist LV barrels. I have a Bartlein with a 8.25- 7.75 in 6mm Dasher that shoots well. It won a 600 yard match today shooting 108 gr. Bergers. With the new computerized rifling machines, the gain can be VERY consistent from breech to muzzle. I don't think that one should try to gain more than 3/4 of an inch with this however. Good shooting...James

 

[stretch257]

Just my thought but won't this shear contact aera by changing twist once the bullet is engraved?

 

[M-61]

Old but interesting was Holland & Hollands "Paradox". Starts at zero twist.