Recently released JENDL-5 data are extensively tested for U-235, Pu-239 and U-238 above the resolved energy region. For this purpose, a sequence of effective multiplication factors along with some spectral indices for well documented bare and reflected cores of fast systems having a hard spectrum and exhibiting larger sensitivity to data of these actinides, 40 parameters in total, are computed by means of a stochastic technique based upon the Serpent code. This approach is then used along with consistent JENDL-5 covariance data to perform adjustments in conjunction with the Asymptotic Generalized Linear Least-Squares (AGLLS) and Asymptotic Progressing nuclear data Incremental Adjustment (APIA) assimilation methodologies. In the provided example the adjustment largely relies on fission reaction rates per atom for Pu-239 relative to the fission of U-235 measured at core center for Godiva and Jezebel and one effective multiplication factor for an intermediate enrichment uranium system. The latter is sensitive to U-238 data.Despite the good performance of the JENDL-5 library, the illustrative adjustment provides overall improvements of the calculation results in terms of decreased mean χ2 and especially reduced variance of the individual χ2 s. More precisely, the posterior mean χ2 of the 40 parameters is close to one as aimed for. This outcome along with the lowered variance signalize a better consistence of the posterior as compared to the prior results despite the small-size assimilation database.