I have a copper clone one, pretty beastly mod. On mine at least ya gotta be careful about screwing the parts together too hard or it can seize, but I think that is due to the softer copper more than anything. Make sure ya watch which way to tighten the reverse-threaded lock too or it may not come off again.
There were a number of manufacturers of the clone, some were terrible, some awesome.
I can't recall which were which now...it's been a few years.
A good 'ol hard-hitting mech though, IMO.
I would be careful of the puny stock springs though if a clone, the weight of the mod plus battery and atty can be too much leading to an auto-fire situation. Happened to me with a AGA-T2 on it years ago. New stiffer springs fixed it though.