I handload 120 gr TTSX. and use staball 6.5 instead of varget or h4350. ( I get 3030 fps and it shoots to about .6") Superperformance runs neck and neck with Staball. I know you want to stay with factory loads, but I am mentioning this for the speed consideration. I shoot a sig cross with an 18" barrel. I was getting about 2650 fps with Federal 140 JSP, that shot to less than .75". I killed several deer last year with it. This year, I wanted to maximize trajectory, while still keeping in mind the total range I intend to shoot. I really think a lot of people get hung up on BC, and long range performance (which is great if you are ringing steel or hunting long range! but within the range that 6.5 CM maintains energy, BC is less of a concern. Meaning bullet efficiency takes over as the more important variable than speed, at a certain range. But up until you reach that mark, speed is more important. So if your intended hunting range is less than than the point where BC becomes the more important variable, why chase BC? Speed kills up to that point.) My intended hunting range is up to 500. I dropped down in weight, to increase my speed. I used a faster powder to increase my speed. I'm using a copper bullet, to offset using a lighter bullet (because a 120 copper will still penetrate and hit like a 147 in lead), and since copper is less dense, it takes more copper to equal the same weight in lead, ie a 120 copper will not have the same BC as a lead 147, but it will definitly have more BC than an equal weight 120 lead bullet, because its longer....hope this reasoning makes sense to you. The point of this is that I would suggest you worry less about going to a heavier bullet for whitetails, and instead try a factory copper in 120. For whitetail it's the best way I know to find the best blend of advantages of speed, BC, and still penetrate well within the kind of ranges that you will most likely hunt whitetail.