Back in the day when that manual was published Lyman accuracy tested (50 yards....) the loads. That 359430 is also a PB'd bullet so the load listed does pretty much max it out accuracy wise....nothing to do with pressure.
I use 32 gr IMR4895 under a RCBS 35-200-FC which is a GC'd bullet. It runs 2162 fps out of my 35 Rem [M91 Argentine rebarreled with a 26" Shilen barrel] at 41,000 psi as measured in that barrel via a M43 Oehler PBL. You might try the RCBS or Lee equivalent GC'd bullet with IMR. Your Contender can Handle that load but suggest you work up as you may not like the recoil.