20 Cal guys----twist rate

[Lucky Shooter]

Is a 12" twist rare adequate for bullets in the 32 to 39 gr range ?

There is very little chance I'd want to use heavier bullets-----most likely
a Vartarg or possibly something on a 222 case.

Us old guys need to play too.

A. Weldy

 

[Mark M.]

12 is good, 11 would be better

 

[Gabe22BR]

11 get ya most all bullets in that range

 

[TAJ45]

What they said Alan. However, should someone other than boutique do a mid to high 40s, think 10, even a 9.
The button rifled 12s are the wild card. 12.3...12.5...???
You have read everything I have I'm sure.

 

[Jdne5b]

I went 11 twist via Xcaliber just for these reasons. Some people report the 12 wouldnt quite shoot the 39/40gr options. If you're at higher elevation that could help.

 

[TAJ45]

Itsa rabbit hole ya don't wanna venture into Alan. Just sell me that small bf rig you snatched as nd be done w it....

 

[hogpatrol]

The 12 can be a crap shoot. I have two 20Ps, one in a ten and one in an 11. Never tried the heavies but both work with anything up to 40s. Side note: Try Randy's BIB 40s.

 

[Lucky Shooter]

Thanks for the voice of experience, the 11" twist seems to be the trick.

Tom, as I've told you several times, she ain't for sale------she has a good home right here.

Com on down and I'll let you shoot her a few times but she stays here. Got it big boy ?

A. Weldy

 

[Bill K]

1/12 will work but a 1/11 is the best, overall. Bill K

 

[Knifeman]

11 Twist!!! I prefer a cut rifled barrel over a button barrel. That being said I went with a Pacnor 11 twist on my Vartarg it will shoot everything from 24 gr to 40 gr. I use it for Coyotes and ground hogs and shoot 40 gr Berger’s.

 

[HillbillyLongRifle]

Pacnors are button rifled barrels!

 

[hogpatrol]

Reread the OP and with a Vartarg, I'd go with a 10 twist for 39s & 40s. For 32s the 11 will work fine.

 

[Woodchk]

I shoot the 39gr. SierraBlitz King , in me .20 Tactical and .20 Vartarg XP100’s . Both have 11 twist barrels shoot great

 

[KY_Windage]

I wouldn't discard a 1:12 barrel if you already have it. Here are four consecutive 5-shot groups at 100 yards with mine shooting 32-gr VMax. It shoots the 40-gr VMax about the same, though I prefer the 32's so I have not shot many of the 40's.

 

[HillbillyLongRifle]

I really enjoy a 20 Vartarg and a 20 TAC

 

[Tommie]

Just get 1-11” twist

 

[TAJ45]

^^^^^ What he said. Why roll the dice if you're going to buy a bbl?
And iirc, Mr Litz has verified that several inches tightening up the twist nets very, very little redux in velocity. Like single digits change.

 

[Coyotefurharvester]

Thompson Center uses a 10 twist for its 204r barrels. I have a Dimension that shots touching groups with bullets from 32-39 gr haven't tried the 40 or higher,yet. My AR in 20p, I ordered a 10 twist. I really like the 40 Nosler bt for coyote.

 

[fyrewall]

I have 11's for both .204R & .20P. Both are OK for mild temps @ 3000 ft. with 40 VMax bullets @ 3650 plus.

Playing around with the Miller Sg estimator gives Sg values with the 40V max @ 3650 @ 75*:

12 twist Sg 1.31
11 twist Sg 1.56
10 twist Sg 1.89

New stuff happens all the time - possibly new longer bullets and demands for shooting at sea level at temps lower than 15*

My next barrel will be a 10 twist.

 

[TAJ45]

Playing around with the Miller Sg estimator gives Sg values with the 40V max @ 3650 @ 75*:

12 twist Sg 1.31
11 twist Sg 1.56 ****
10 twist Sg 1.89 ****
New stuff happens all the time - possibly new longer bullets

My next barrel will be a 10 twist.

There ya go . . .