I am building a 20BR with an 11 twist shooting 39gr. I am thinking about chambering an 8.6 twist barrel as well and loading the 55 as well. Can you tell me the benefits of shooting the 55 over the 39gr. Or what if any differences in performance. The rifle will be used for target shooting and prairie dogs shoots. Long range accuracy with low recoil are my priorities. I have searched and can’t find any comparisons. Thanks for your insight.