I have a 5" FA83 500 JRH converted by Jack H. Here are a couple of loads for RJM
These are all with Starline Cases and Fed 210 primers ( CCI 350s chronoed the exact same velo as the 210s in the below 4227 load)
10.0gr HP-38 440gr WLNGC (Rimrock) ........ 900 fps
15.0gr HS-6 440gr WLNGC (Rimrock) ........ 1,050 fps
26.0gr 4227 440gr WLNGC (Rimrock) ........ 1,200 fps
The following is my current go to load (about as much recoil as I can tolerate any more).
325gr Swift A Frame, 33.7gr H110, .............. 1,320 fps
The hornady 350gr with 33.7gr H110 .......... 1,355 fps
I shot these off the toneau of my pickup at 52 yds with a 4x leupold on the 5" M83. The 26.6 was 4227, the rest were 15gr of HS6.
Top gun in picture
FWIW,
Paul