20 Practical Twist Question

[SVT_Tactical]

How will a 20P in 12 twist be with 35gr berger? Have several 1000 of those now. That would be the heaviest bullet I'd want to play with but if the 26gr barnes VGs group good it would likely be my standard. Trying to decide on barrel twist. Found 12s in stock.

 

[Tommie]

It’ll be fine with that bullet

 

[GLShooter]

It'll work but I would want a 10 for more flexibility.

Greg

 

[L.Sherm]

11tw will be fine in anything up to 40 grain

 

[EvanB]

Heavier bullets faster twist, 1-12 twist 32-39 grain (some 40's depending on gun. 1-11 good to go up to 50 grains. For anything above that, why not just go with the tried and true 1-9 common twist for .223.

 

[HillbillyLongRifle]

12 twist will be fine

 

[HillbillyLongRifle]

I have had many true 12 twist barrels and they hammer with 40 gr and lighter bullets.

 

[Coyotefurharvester]

My 204R TC barrel is a 10, when I put together a 20p upper I went with a 10T. Both shoot 32-40's accurately, including 35 gr Bergers which are a good fur bullet. I also like the 40 BIBS for coyote.

 

[Bill K]

The best, all around twist in the 20 calibers is a 1/11. It will handle many very accurately.

 

[L.Sherm]

1-11 good to go up to 50 grains

In a 20 cal?

 

[jpx2rk]

I've been trying the 34g dogtown bullets in my 11T 20P with good results. I realize there is a big difference in quality of bullets, just an FYI. Happy with 200 & 300 yd results, not one hole results, but accurate enough to give a pdog/sage rate a hair cut if/when the wind blows that little bullet off the intended target.

 

[EvanB]

In a 20 cal?

Yes, in a .20. I shoot a 1-12 but use 32-39 grain. 40 grain needs it faster to stabilize.

 

[RegionRat]

https://bergerbullets.com/twist-rate-calculator/

This twist rate stability calculator is free to use and Berger even has a 20 cal 40 gr in the drop down menu so you don't even need to look for the bullet data. There isn't too much research required to put in a different bullet if you want to.

Just pick the Berger 40 grain as an example, and put in your muzzle velocity estimate and play with the twist rates. At sea level, you are better off with a 10 than a 12, but anything higher in elevation just gets better.

 

[L.Sherm]

Yes, in a .20. I shoot a 1-12 but use 32-39 grain. 40 grain needs it faster to stabilize.

I seriously doudt you will get a 11 twist to stabilize a 50 grain bullet unless your at some very high elevation, Berger doesn't even make the 50 anymore..

 

[7315br]

I seriously doudt you will get a 11 twist to stabilize a 50 grain bullet unless your at some very high elevation, Berger doesn't even make the 50 anymore..

Sherm, I tried the 50 gr 20 cal Bergers in that crazy 20-223 WSSM I built with a 11-twist Kreiger. It would barely stabilize them (4,000 fps) and the groups were no better than 3/4" at best. The 55 gr Berger was all over the place! I set the barrel back and made a 20 PPC out of it. It shot both the 39 gr Sierra (4,200 fps) and the 40 gr V-Max well (hi-1's)...soooo to me it wasn't the bbl, but the twist with the wrong bullet. The groups were shot above 4,500 altitude. 7315br

 

[TheCZKid]

I've got a 10 WOA barrel, and it does well with 40's loads, still trying to find as tight of load on 32's. I'd think a 10 or 11 would work well around the 35 grain range. The quality of the barrel would likely be at least as important as twist rate.
Are you building a bolt action or gas gun?

 

[revoman]

I recently built a 20 P and chose a 1-11 twist in the hopes I could shoot the 40gr vmax bullets. The 32gr vmax's have a wide range of accurate velocities, but I couldn't get the 40's to group. If I recall correctly, the Berger twist rate calculator suggested for a 1/10 twist at 7,000ft elevation (father-in-law lives at that altitude and has many p-dogs). Seeing how I recently found a boat load of 32gr vmax's for $.17/each I don't have a problem either way.

 

[L.Sherm]

40 grain bullets not shooting in a 11 twist barrel is not a twist problem, did you confirm its a 11 twist?

 

[redrockranger]

Yes, in a .20. I shoot a 1-12 but use 32-39 grain. 40 grain needs it faster to stabilize.

As i read your first statement . It indicates a 1-11 tw will stabilize 50 gr bullets ?

 

[Tommie]

As i read your first statement . It indicates a 1-11 tw will stabilize 50 gr bullets ?

Surely he fat-fingered that post. No way will 1-11” twist stabilize a 50 in a 20P