Also fits srd338 can - SIG SAUER QD Taper-Lok Muzzle Brake Mount For SRD762-QD 1/2-28 TPI SRD-762-12X28-B

What I don’t understand is why they don’t list this is also SRD338. I have both and used a Venir calipers to compare and they micro out to be the same dimensions except the bore hole is slightly larger on the 338 versus the SRD 762. So you can run this up to 30 Cal bullets but step up to 338 you need the larger cal. The problem with the sig catalog is the 338 does not offer 1/2 x 28. 338 only has 5/8 x 24 which is standard on ar10.