Twist rate for 20 Vartarg

Buster Hindend

Buster Hindend

New member
So I'm looking down the road (way down the road) at a 20 Vartarg build. I already have an 11 twist barrel on another 20 cal rifle. So I was wanting the Vartarg for bullets in the 32-35 gr range and no heavier than 35 gr. I have the 11 twist for the 39 BK. So I'm wanting a rifle that would shoot lighter bullets.

Would I need a 12 twist for this weight bullets or would an 11 still suit my needs?
 
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I have a barrel on order for a Vartarg build and went with a 11 twist just in case, I have 2 204 Rugers a 12 twist and a 10 the 12 will not shoot the 40's at all its great with the 32 to 35 gr bullets.
And the 10 twist will shoot the 32's on up to the 50's.
I am planning on just loading the 32's in the Vartarg I know the 11 twist will shoot the lighter bullets and I'm pretty sure a 12 won't shoot the heavier ones but every one is differen't
 
My 1:12 Rock Creek shoots 32Gr V-Maxs wonderfully... No experience with anything higher.

When I rebarrel my .204R, I'm definitely going 1:11 or 1:10 for the 40gr V-Max stash I have.
 
Originally Posted By: Buster HindendSo I'm looking down the road (way down the road) at a 20 Vartarg build. I already have an 11 twist barrel on another 20 cal rifle. So I was wanting the Vartarg for bullets in the 32-35 gr range and no heavier than 35 gr. I have the 11 twist for the 39 BK. So I'm wanting a rifle that would shoot lighter bullets.

Would I need a 12 twist for this weight bullets or would an 11 still suit my needs?

The 11 will work just fine. It is a bit faster than necessary to stabilize the 35Gr, but the 11 will work fine, plus you could go heavier if the need arises. It won't hurt you, if that is what you are asking.
 
Originally Posted By: Tim NeitzkeIf you want max speed, use the slowest twist you can get by with.

Thanks Tim that's what I was trying to ask,albeit poorly

So, if I want to shoot bullets no heavier than 35gr is 12 twist the one I want
 
It would get my vote. I no expert though .
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Originally Posted By: Buster HindendOriginally Posted By: Tim NeitzkeIf you want max speed, use the slowest twist you can get by with.

Thanks Tim that's what I was trying to ask,albeit poorly

So, if I want to shoot bullets no heavier than 35gr is 12 twist the one I want


In this case, we are talking about the difference between a -11 twist and a -12 twist. No velocity change for practical purposes.

Stability numbers do however change. With the -12 twist the 35gr Berger will see Sg numbers in the 1.25 range. With the -11 twist the 35gr Berger will see Sg in the 1.50.

1.30 is where you want to be or above in theory. So the -11 twist will produce a more stable bullet potentially.

I would go with the -11 twist unless you want more barrel length than it has.
 
My custom 204R upper was a 12 twist, I never did try 35 Bergers in it. The new owner does shoot them though.

When I had it for sale ,I could have sold it 10 times over,if it had been a 10 twist.

That being said 11 is in the middle .
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I'm sorry Buster, I thought you already had the 11 twist barrel ready to go. My bad.

The -12 twist in 20 cal. is minimum. More suited to the 32gr pill that Ruger was pushing with the .204. Had Ruger twisted the .204 in -10, it would be a whole different playing field for the .204R. A -10 twist would be better for heavy pills, and would make the .204 more versatile. Ruger was pushing velocity and trajectory with the 32gr. It looks better on paper. So they went with the -12. Not the best for the cartridge, but good for sales.

Any way, the Vartarg has less velocity than the .204R, so a -11 twist will always play in your favor. The -12 will work as it does in the .204, but rpms play the role of stability. The more the better, to a point.

Call Your bullet maker and ask them what would be best for the bullet.

MV X 720 / twist = RPM. They will tell you the RPM the bullet needs.
 
Originally Posted By: SmokelessI'm sorry Buster, I thought you already had the 11 twist barrel ready to go. My bad.

The -12 twist in 20 cal. is minimum. More suited to the 32gr pill that Ruger was pushing with the .204. Had Ruger twisted the .204 in -10, it would be a whole different playing field for the .204R. A -10 twist would be better for heavy pills, and would make the .204 more versatile. Ruger was pushing velocity and trajectory with the 32gr. It looks better on paper. So they went with the -12. Not the best for the cartridge, but good for sales.

Any way, the Vartarg has less velocity than the .204R, so a -11 twist will always play in your favor. The -12 will work as it does in the .204, but rpms play the role of stability. The more the better, to a point.

Call Your bullet maker and ask them what would be best for the bullet.

MV X 720 / twist = RPM. They will tell you the RPM the bullet needs.

Thanks, now that us info I can relate to. Thanks for breaking it down for me. I'm really wanting to shoot 32BK or 35 Bergers in this (future) rifle and wasn't sure that since I had an 11 twist on another rifle if I got another 11 twist for the Vartarg if I would be stuck using the same weight bullets as the other .20 cal. I don't want two .20 rifles shooting the same bullets.
 
Originally Posted By: SShooterZWith the right powder, brass and bullet combo, you can load the .20VT to .204R velocities.

Check out http://www.saubier.com/forum.html

Adam Bentley was getting 4000FPS I believe out of his .20VT with AA2200 and 32gr pills.


That's the direction I want to take this Vartarg, just didn't know which twist rate would accomplish it.
 
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