Exactly what I was looking for
What bullet weight can I shoot in my (1/9, 1/8, 1/7, etc.) rifle?
This is undoubtedly one of the questions that is asked the most. The answer depends on many things, but here are some rough guidelines for those that don't care about the details:
1-in-14"55gr or less
1-in-12"35gr up to 55-60gr
1-in-9"45gr-75gr, possibly up to 77 if you're lucky
1-in-8", 1-in-7"45gr - 80+gr
To find out for sure if your bullet will stabilize a given bullet which is on the fringe, you'll have to try it out in YOUR rifle. Some people's 1/9 can't stabilize 75gr bullets, while others can get away with 77gr bullets in theirs. Technically, it isn't about the WEIGHT, but the LENGTH of the bullet, as well as air density and velocity. A simplified method for determining the minimum rifling twist rate for a given length of bullet is given by the Greenhill formula. A Google search will show many sources for those interested in a more in-depth discussion. If you have the length of your bullet, and just want a look-up table to see what twist rate you need, refer to this page. If you really enjoy the in-depth mathematical treatment of the subject, check out these pages.