[Oxford]

There is also a point of diminishing returns in going to a twist rate on the slow side. For example look at the chart below. The difference in grouping ability between an 8" twist and an 8.5" is .016". But the difference between a 15.5" and 16" twist is just .004".

So, my advice is pick a twist that is best for the bullet being used without going too slow and getting a stability factor too close to 1.0.

TWIST RATE IN INCHES/TURN EXPECTED MOA
GROUPING
8 .272
8.5 .256
9 .242
9.5 .229
10 .217
10.5 .207
11 .198
11.5 .189
12 .181
12.5 .174
13 .167
13.5 .161
14 .155
14.5 .150
15 .145
15.5 .140
16 .136