I just moved away from Easton Axis and Legacy's this year to try the Safari Tuff Taipans. So far I have been very satisfied, they're tough, priced well, and my biggest compliment is you buy the whole system in one stop. Also, they're a .204 diameter arrow.
I have a Credo in UM Tikka rings, the other day I wanted to see how much elevation I had left and was disappointed to find out I only have 13 MOA left of the spec’d 100. Are other Credo owners seeing the same? 2.5-15x42 HX.
I've been using Thoro Clean with a 30 cal Iosso brush in my 6.5 PRC. I've had the most carbon ring issues in my overbore cartridges and this has proven to work best for me. Letting the ring soak in some Boretech carbon solvent has also been effective, just a slower process.