I have a t3 lite ss in. 308 and dont have a caliper to measure the muzzle of the barrels outer diameter. Anyone happen to know the outer diameter? I am asking because I want to get the barrel threaded for a 5/8×24 tpi muzzle brake. Is the barrel thick enough for that thread pattern?

no you would need to use a 9/16×28 and I believe all the lite barrels are .620.  I was able to use a 5/8's brake but only because I had my barrel cut to 16″.

I ended up using one of these and it works great on my 300wm.  I think it weights 4oz.
https://kahntrol.com/products-page/clamp-on/ksmb615/

Vixty is correct…I had my 300WSM threaded to 9/16-24, it was the only way to make it work.

This muzzle brake tamed my 300 down to a 223, I'm not joking!
The ports are designed to make it way more effective than a Vais, and they work,… but its loud as hell like all the others!  Tested and proven to almost a 70% recoil reduction in a 300WM or 300WSM