best twist

[anothergunnut]

I need a replacement barel for a legally registered M-16. What is the recommended twist I should be looking for for (primarily) 55 grain bullets.

[Circuits]

1:9 is the most versatile and generally most available twist in current manufacture. Good for 45gr to about 69gr, depending on bullet construction.

1:8 or 1:7 if you want to try 77gr SMK's, or heavier/longer.