Gain twist

[jessej]

What manufacturer can or is willing to build a gain twist bbl starting at almost straight(30 or so) ending at a 7.5 or 8 at the muzzle?

 

[jessej]

And has this been tried already?

 

[Sniper18]

I have one that's similar twist but in 7mm that's a bartlien. So might be worth a try to get ahold of them.

 

[Bang4theBuck]

What do you know about that approach that you can share? Seems like more gain than I've ever heard of by a factor of 5x.

 

[Northkill]

I too would like to know what Bartlein will tell you. Are you trying to lower pressure on an overbore and/or gain speed or twist without ripping a bullet apart?

 

[jessej]

Just looking to experiment.
Always looking for a way to do something better than it's currently being done.
Better May mean more accurate, or it could mean faster….

 

[Bang4theBuck]

I am not a fear mongering guy, and someone has to breach the boundaries to advance technology, but I can create all kinds of problem scenarios in my head with starting a bullet straight and then rapidly increasing the spin rate. All I can say is good luck, and be careful, and take good notes on the first try!.

 

[KyCarl]

The rate is way too fast from 8.5 to 7.5 might work but from about straight to 7.5???

 

[jessej]

You may be right.
Explain why…..

 

[jessej]

The only issue I can see would be the huge hour glass engraving mark. This would limit projectile selection to solids.

 

[jessej]

Update.
Emailed bartlein. Within minutes, Mr Mark called me. Great conversation with a great guy.
They have done radical gain barrels, but not currently due to existing demand and lead time. He did not discourage they idea. And Steves name was mentioned. So now my wheels are really spinnin.

 

[KyCarl]

OK I'll try when you first fire a rifle the bullet goes from 0 fps but moving about straight at 3000 fps then trying to spin it
seems like it would shear the bullet smaller?

 

[jessej]

Valid point of view.
So let's say, Not starting straight, but close. 1 in 30. Then, Steadily increasing for the length of the barrel to the final fast twist. Seams to me this would be less chaotic for the projo

 

[Northkill]

I was thinking Bartlein limited their gain-twist options to 1" differential, but it sounds like they are willing to stretch that from what they told you. Mark is a good guy there at Bartlein. Knows his stuff.