Barrel twist and progressive barrel twist

[ericbc7]

Has anyone done some evaluation on progressive barrel twist? in other words is there any advantage to starting a rifling twist at (for example in .30 cal) at 1:14 then transitioning to 1:10 or 1:9? I have no idea if a gradual increase in twist rate would ease the transition from 0 fps to 2800 fps in 24 or 28 inches but I am very curious to know if it has been tried.

 

[Keith Glasscock]

Yes, several manufacturers offer gain-twist barrels.

As for performance, I'll leave that to those shooters that have tried them.

 

[ericbc7]

are there any competitive shooters that are using this type of twist gain?

 

[Hippy]

Tony B used a "Gain Twist" Bartlin when they 1st became popular ( Make that popular again) and had positive results--BUT Tony can shoot a McDonalds Straw and do OK LOL

Jim

 

[Grimstod]

I would really like to see some data on this too. I have seen this topic come up on other forums but no one has ever posted any test results.

 

[clowdis]

I shot a Bartlein palma barrel for a couple of years with a 12.5 to 12 twist. My theory is that any slowing of the twist is detrimental to accuracy so a slight gain would insure that that didn't happen. It shot no better than any of the other barrels that I had on the rifle over the years. It has been around for centuries but really gained popularity with the lead bullet Scheutzen shooters in the late 1800's. Their thought was that a gain twist was less likely to "strip" on a lead bullet by giving it an easier more gradual spin. Acceleration actually does the same thing.

 

[butchlambert]

Yes, several manufacturers offer gain-twist barrels.

As for performance, I'll leave that to those shooters that have tried them.

Can you give us a list of several manufactures that do this?

 

[Keith Glasscock]

Forgive spelling errors, but here are the ones I know of:

Krieger (at least they did a few years ago - there were articles in the daily bulletin)
Bartlein (they call it T-style now)
Ron Smith, RKS barrels (Canada)
Obermeyer (they only do it for ordinance barrels right now)
Lilja stopped with their gain program a while back as did Pac-Nor

So my several really turned out to be 3 that you could talk into making you one. Guess I remember too well what was available several years ago, and am not keeping up with the times...

 

[butchlambert]

Forgive spelling errors, but here are the ones I know of:

Krieger (at least they did a few years ago - there were articles in the daily bulletin)
Bartlein (they call it T-style now)
Ron Smith, RKS barrels (Canada)
Obermeyer (they only do it for ordinance barrels right now)
Lilja stopped with their gain program a while back as did Pac-Nor

So my several really turned out to be 3 that you could talk into making you one. Guess I remember too well what was available several years ago, and am not keeping up with the times...

I don't think Kreiger offers them any more.


I would be curious as to how a button rifled barrel could have a gain twist.

 

[Eddie Harren]

Butch, I'm with you. I'd like to see a gain twist, button rifled barrel as well.

 

[Keith Glasscock]

As busy as all barrel manufacturers are, special items are going to be harder and harder to get.

I bet that krieger would make one *if* they weren't overloaded with orders. I know nothing about the P&W machines, but I can't imagine that it doesn't take a bit of setup to do a gain twist.

The only thing I know about button rifling is that the barrels shoot good when done right.

 

[Eddie Harren]

Busdriver, something else you should know about button rifled barrels is, the twist rate is ground onto the button. Gain twist would be next to impossible to achieve.

 

[butchlambert]

Busdriver, Eddie is correct. Most have a sinebar attached to keep the button in a constant twist and eliminate chatter.