Whoops, an error. My gun is actually marked ZV4, not VZ4. It was purchased many years ago from an importer who brought in a bunch of "junkers" from Europe. They were sold in lots of five as they came from the container. My lot included a Rossi, two IZH IJ 38, one IZH IJ 22, with plastic Soviet Union domestic stock and the ZV4. The IZH 38s were in decent shape so I refinished the better ones' stock and resealed both. A gas spring from a guy in Izhevsk was installed in the better gun. Even though far harder to cock than the original spring, it made almost no difference in power. I should have expected this considering the very short piston stroke.