Twist rate questions

[Hurley0816]

How heavy bullet can I shoot out of a 22-250 with a 1 in 12 twist? And same question for a .223 with 1 in 9? Would also like to add that it will be factory ammo. Thanks

[drybean]

on the 223 iwould say 69gr

[82boy]

The 22/250 I would say 69 gr, and the 223 I would say 77. I have done both and have not had a problem in a couple of guns tested.

[11fcns]

i have a 22-250 with a 1:12 twist and probably wouldn't go above 60gr. most barrel makers seem to list that as a max for their 1:12 barrels.

[GaCop]

I had good accuracy with the 75 grain A-Max in my 1 in 9 twist Savage.

[geargrinder]

It also depends on the design of the bullet. Flat based bullets will stabilize easier that boat tails.

Meaning you can go heavier with flat base than boat tails.

[Altair]

I don't have much experience with 1:12 barrels but I do with 1:9. All of my 1:9 AR barrels will shoot the Hornady 75gr BTHP but I know there are some 1:9 barrels that won't stabilize them. Whether this is a manufacturing issue (ie all the barrels aren't exactly the same twist) or if it is just right on the edge and some barrels like them while others don't I don't know. I know if you stay 69gr and lighter they will all stabilize in a 1:9 and if you go over that it is trial and error. Also, something like the 70gr Barnes TSX won't stabilize in the same 1:9 barrel that a 75gr BTHP will. Since the Barnes is all copper it is lighter and very long for its weight. You have to go down to 62gr for the 1:9 in the TSX.

[khuff]

Well according to "charts" (in theory) a 223 with a 1 in 9 (many are 1 in 8 really=80 grain BT) twist rate is 73 grains BT, that does not take into account the length of the barrel. A 16" barrel will not act the same as a 24" barrel, it's not logical.

If you use "charts" a 22-250 with a 1 in 14" twist rate can not stabilize anything over 55 grains FB, here again that does not take into account the length of the barrel.

223/5.56 twist rates:

Barrel Twist Rate 1:14" 1:12" 1:9" 1:8" 1:7" or1:6.5"
Max Bullet Weight 55gr FB 65gr FB 73gr BT 80gr BT 90gr BT VLD
taken from 6mmbr.com - credits to:

Acknowledgments: Big thanks to Andy ("Graymist") for his load data and many hours spent measuring brass, to Jason for providing some cool photos, and to Sierra Bullets, for making its .223 Rem load data available. Berger, Sierra, and Hornady also provided bullet samples.

Graymist is a ton more knowledgeable and more practiced than me.