I have a 4.5 x 14 that has the B&C reticle. I use it on my Remington 700 in 7mm Mag. When you get the scope it comes with a chart that lists the calibers and at what power you have to use to use the reticle. I set my scope on 10 for my 7mm caliber because that was where the chart told me to set it. I am currently looking for my instruction book, I have recently moved, but I believe, for the 30 calibers with that grain bullet, you are going to have to use the 14 power. This is the main reason I do not like the reticle- it is very constricting. Hope this helped you.