I am looking for a short brake like a Vortex or a Troy so would need compatable threads.
not sure about the troy
smith enterprise vortex flash hiders are not legally aquireable due to strict US export controls (same with all flash hiders unless it comes attached to a rifle on export)
you can get these two items that WILL fit your chinese barrel by re-using your chinese castlenut.
springfield armoury muzzle brake - call springfield and order (it's a long unit though and you want short)
smith enterprise coast guard (good iron) muzzle brake - Armtac (site sponsor)
chinese castlenut (muzzle) threads are metric, US barrel threads are imperial , so no, they aren't the same. However, back when smith enterprise direct connect vortex flash hiders were trickling into canada, many of us found that they did thread on to the chinese barrels safely.
not many options for replacing the muzzle device on a factory barrel up here in canada and most of what is availlable stateside is extremely hard to get either by law or by supply/demand
the other option that has been VERY popular, is to buy a 22 inch barrel or whole rifle and have an outfit like ellwood epps or dlask arms, cut & crown to 18.5" and thread 1/2x28 as there are lot's more options for muzzle devices, just make sure what you buy has clearance inside for a .30 CAL projectile
a gas lock type sight will be a must if you go this route.
hope that helps ya
