Here's what I had to do to mine to get it to work:
1. Build up tip of cocking lever w/weld to make cocking easier.
2. Build up upper surface of mag catch w/weld & enlarge receiver cutout to seat mags higher. 3. Installed "+4" rollers.
Now she shoots 100% reliable & groups 2.5 MOA with either Australian or Hirtenberger ammo.
The downsides?
1. Stamped carbon-steel receivers not set up for scope mount (stainless ones are though).
2. Safety is ass-backwards.
3. Recoils somewhat harder than an FAL, M1A, AR10, etc.
I think I would go with paying more for a PTR-91. However, if you must go cheap consider the cast stainless steel receiver & inspect as follows:
1. Unground bolt.
2. Mags seat properly in relation to bolt.
3. Easy to cock.
4. Check sights by bore-sighting.
A $300 rifle & $5 mags is seriously tempting (ss receiver more like $400). From someone who's "been there, done that", they can be safe & reliable, but you're definitely taking a gamble, and maybe need to do a little home gunsmithing. Your call.
As for mine? I'm still undecided. I may rework & reverse the safety, keep it, & shoot the hell out of it. Or I may trade it for a PTR-91 someday. The roller-locked system is kinda growing on me. No gas system to clean...