I assume the reason for your question is to suggest what OAL you should use rather than a fasination with what we are doing?
If so, I don't think we would be any help at all. We would have to test your chamber and bullet, any bullet, for max OAL and then do a series of tests seating back from the lands contact point. You will too. Good luck!
I have loaded a number of rifles with the Barnes TSX bullets including a couple in 270 Winchesters using the 130 TSX's. My advise is to follow the information that Barnes provides with your bullets. You need to load the bullets 50 thousand off the lands to start. You may have to move them a little closer(.035 as given by Lngrnghunter) or a little further away depending on how accurate they shoot. The reason I can not provide a COL that will work in your gun is that all rifles are different. If you don't know how to determine where your lands are ask and someone will help you.