Going a different route with my Lapua. Here’s the link to Surefire’s website with all the details. https://www.surefire.com/338-muzzle-brake.html Model # is MB338SS03 and came off of a CZ 550 HET 338 Lapua. It is 3/4x24 thread pattern. I’d like $100 shipped via PayPal friends and family.