Barrel info

[Chad280]

Looking to build a 20 practicle or vartarg. What twist is best for the 30-40 grain bullet range? And what groove? 3 or 6 groove?

 

[Grimstod]

This is your best friend. http://www.bergerbullets.com/twist-rate-calculator/

 

[Gabe22BR]

1-11 will get you there

 

[Rick in Oregon]

All my .20 caliber rifles wear 12 twist barrels, except one, my 204 Ruger Match, which wears an 11 twist. If you intend to shoot the 40's, you'll want the 11 twist, as 12 twist is marginal for stabilization of the 40's, especially the V-Max, which is long for weight.

If you go 11 twist, you won't have to fret about any bullet weight in the range you intend to shoot.

 

[nmkid]

I went with the 1:11 because I wanted to shoot the 30-40. My .20 Practical shoots the 40 gr. Vmax so good that I haven't gotten around trying the lighter bullets.

 

[Knifeman]

1:11 twist. Build a Vartarg and you won't regret it. Bob Green the gunsmith who is building my second vartarg. I'm getting 3700 fps with 40gr Berger 's.

 

[pacificman]

I have a 12 twist for my vartarg but will shoot only 32 grain bullets with this one. I use 11 twist for the
20 practical as I use 40 grainers fro this. As others have mentioned an 11 twist in either would allow you
to use 40 grain bullets. 3 groove barrels in both...very easy to clean.

 

[Chad280]

Thanks guys

 

[fyrewall]

1-11. I only shoot 40 VMax's in my 1-11 rifles. I have a 1-11, .20 Practical and would not consider any other twist. My .20 rifles have 4 L-G barrels and clean up real easy and I would expect a 3 L-G might be better for cleaning. There is also some discussion of odd number L-G barrels having some perceived advantage as each groove has an opposing land on the other side of the barrel - I have not figured that one out yet.

 

[223Randy]

I used a Green Mountain SST 25" long by 1.06" diameter, 5mm/20 caliber, 1:12 twist, 416 stain steel, turned on centers, air gauged, stress relieved, button rifled, .201 bore/ .205 groove, weighs 6.0lbs
Did my own chamber, shoots 34gr dogtowns at dime sized groups of 5 @100yrds