OK, as I mentioned in a previous thread I am in the process of replacing all of my Leupold MKIV's with USO ST-10's. One of the MKIV's is on my Barrett M99. I e-mailed USO and inquired about using the ST-10 on a .50 BMG and they said it "Should" hold up. I was looking/hoping for a more concrete answer before I drop $1300 on this scope. Have any of you guys used a ST-10 on a .50 BMG and if so, how does it hold up?