Saturn save files Mednafen to Retroarch beetle

Anyone have trouble transferring Sega Saturn  save files from Mednafen standalone to RetroArch beetle? They both use the same file types bck and bcr, but Mednafen includes a long hash in the filename and is a smaller size. Just renaming the files and copying to the RetroArch Sav folder won't work. I used the Saturn save parser to get the correct file size for Iron Storm and the game detects the sav file. However the game freezes up after loading the save. 

In the past, I've run into similar issues with standalone mednafen. When i bought a new computer, I downloaded the latest version of mednafen and copied the over the save files. Certain games would not detect the files. I never got it working 100%