Tools- i have a .243 with 1- 12 twist hart barrel on a rem 700. i have shot up to 87 and 88 grain berger and it shoots those excellent . i have not shot a 90 grain scenar. i also have a 6mmbr with a 1-8 krieger barrel. i only have 25 or 30 shots through it all heavy weights 105-107. i believe it will shoot everything 55-107 good. read some on 6mmbr.com . for 88 and down my 1-12 is great.