Attached is the output file for SRIM. SRIM outputs stopping power. From there, the CSDA range can be calculated. Extrapolating to 86.26 keV gives a stopping power of dE/dx = 846.69 keV/mg/cm2. Dividing by the energy and inverting gives a value of 0.102 mg/cm2.
Geant4 outputs the CSDA range as 0.08391 mg/cm2. There is an 18% difference in these numbers. The projected range was a 22.2% difference.