Got a romy kit and Ewbank receiver. I have the trigger guard and front trunnion temporarly installed. A mag will not fit.It catches on the back on the mag and will not snap in. If I eggshape the trunnion hole in the forward direction and slide the trunnion up a 1/16th the mag will snap in. Or, if I grind a 1/16th back (receiver and trigger guard) under the mag catch latch it will fit. What would be the best way?

Thought at first it was the small rail between the bolt travel rail and mag dimple. I removed it by grinding which was no help.

Thanks for the help.