Hey guys. I'm currently in the process of rebarrelling my Remington 700 Sendero that is currently a .338 win mag. More than likely I'm going to replace the factory tube with a Lilja but one member recommended instead of rebarrelling in .338 win mag go with .338 ultra mag for better ballistics and would love to do this if it will work with my current bolt which had the magnum bolt face for the win mag cartridge. I purchased a PT&G one piece fluted bolt from Dave Kiff out at PT&G and can't send it back. Also being as I am rebarrelling can I use a .375 CheyTac or a .408 CheyTac cartridge in a standard Remington 700 long action receiver with the appropriate caliber barrel or are they too long? What about rebarrelling in .338 Lapua? Suggestions guys. Thanks for the info.