The AS and VSS not using subsonic is a bit weird but AKs having slower firerate than AR platforms makes sense since AR platforms tend to have a higher cyclic rate.
@@CorpraliusCotrel mostly servers from 3.0 is dead but map creator said about big update in the next month however he didn't mention when exactly will be
DRTP is a drop from Soviet megazombies, you can find focus rifle parts at the crashed satellite (note that you have to have the related quest done in order to craft it), DF-9A can be obtained by upgrading the DF-357L (the deagle with a sight) with a weapon mod kit, zolash bolt can be a drop from civilian zombies / locations and AR-16 NAIL is obtained by upgrading a nailgun mk.II with a weapon mod kit and an AR-16.