Hi, I just replaced the barrel of my Sako Vixen in .223 Rem with a Douglas XX barrel with a 1 in 10 twist. What would be the heaviest bullet I can use? Thanks.
Jess

A 1 in 10" twist will likely handle bullets weighting in the 60 grain class (60 -69). May be a little heavier. Velocity also plays in the equation.
The only way to know for sure is to load some up and shoot them. I think this is part of the reloading "fun".

muck

What is important is the length of the bullet. Obviously with lead and copper, so much material has a basic length. Then you go to form. VLD? boat tail? The military bnullets were meant to tumble in the 1 in 10. Now its 1 in 7 with heavier bullets. The old 63 grain, short stubby nose would stabilize in most 1 in 14 at reasonable velocity. 1 in 10, flat base and normal point, up to 70 for sure.

Barrel makers web sites have tables to help you choose barrel twist for preferred bullet. You could use them backwards. Shilen. Obermeyer. PacNor. Krieger. benchrest.com has ads. Luck.

I would say the 68-69 grain match bullets, or the 70 grain hunting bullets.

I rebarreled my Sako L461 with a 223 MADDCO barrel. I also went with the 1 in 10 twist and use 65.5 gns projectiles and could not be happier.
Pete

I am sure that the 74 grains RWS kegelspitz wil work fine in the 223 with 1-10 twists...

How short and compact it is can be seen here.