Re: psl rifles
The biggest problem with the PSL-54s, ROMAKs, FPKs, or whatever the hell they're calling them now; is the optic.
If you get one with a LPS/PSOP optic, figure out which one you have, sell it to a collector and have someone fabricate you a quality mount and get a modern scope on there.
Even these cheap guns have gotten close to 1MOA from various folks with better quality ammo. Keep your eyes open for 7N1/7N14 marked ammo, typical surplus light ball doesn't really do the trick.