Pretty much the only direct reference to Izd. 30 HPC pressure ratio to date is a recent disclosure by Salyut in connection with the engine's first flight. This stated 6.7 (so in my range of estimation, albeit at the lower end) but there are a couple of reasons to believe the figure might not necessarily reflect the final product.
Firstly, it's generally understood that the HPC is Saturn's responsibility (as is overall project leadership), secondly the mass flow specs quoted along with the pressure ratio don't match the range expected for the full size engine. Depending on whether you take them as referring to actual or corrected flow they indicate a sub-scale demonstrator or an AL-31FM2/3-class engine, either of which (in combination with the source being Salyut) would suggest they may rather apply to Salyut's losing bid in the initial competition for overall leadership of the project.
As for WS-15, 7.1 in a 6-stage HPC would be ok (it's worth mentioning in this context that if Salyut's quote refers to their AL-31FM2/3 compressor it would represent 6.7 from six stages) but still a bit lack-lustre. Even accounting for the fact that average stage pressure ratio drops slightly as you add stages to a given design it works out to a lower figure than the EJ200 (which in turn would be beaten by Izd. 30, even if we assume 6.7 is correct for that engine instead as it would then be done in only 5 stages). I suppose this would mirror the situation seen with the CJ-1000A and PD-14 quite nicely though.
