Try to get more information on what brand/builder they are from. Century on IMBEL receivers are good to go. They were imported with ban-compliant furniture, and non-threaded muzzles. Century G1 or R1A1 sporters can be iffy. I have a G1 sporter that shoots awesome now, but had to be redone in order to get that way. DSA is usually the way people go nowadays since it's the only domestically produced version. QC can be a crapshoot, but at least they're still around to fix stuff. Arizona Response Systems is one of the best FAL smiths around, along with AZEX is another one. Entreprise receivers can be good, but a lot were bad, according to the stuff I've seen. There are a lot of FALs put together by shadetree gunsmiths, so be wary.
If you can get more info, come back and let us know, please?
