Verification of SCR Driving Circuit
The major problem appears to be that your SCR Cathode will start to rise as the device turns on and critically reduce the gate drive. You certainly won't meet the minimum t(gt) of 2 uS and may find the SCR turns on very slowly.
You should move the SCR to the ground side of the inductor.

Perhaps more like this: 







simulate this circuit &ndash; Schematic created using CircuitLab