I've got a T3 I load for a friend with 140 TSX W760 , 215M primer , RP Brass ,2970 Ft/sec with no pressure issues.I do have them loaded to 2.780", what the exact jump is I didn't measure but this works well.
Use W760 for many 7/08 loads
Like bearhunter says, some like it hot, this one certainly does.
Don't stress about components , just start low and work up, I do however endorse the Lapua brass and will not use Federal unless I absolutely have to.
I would however discourage the use of a TSX out to 4-500 in the 7/08 , for that you want something more fragile, as the TSX need speed to open up properly.