Gun Talk What are the differences between 4.5mm and 5.5mm folding trunnions

The difference is the size of the hinge pin for the folding stock one uses a 4.5mm pin the other a 5.5mm pin. Maybe you know this already but it’s not just a matter of installing a new trunnion and a stock, you would need to drill the front hole in the receiver and thru the front trunnion for the front latch pin, then cut the square hole in the left front of the receiver for the stock latch then you would have to cut the holes in the rear of the receiver for the stock release latch and cut the rear of the receiver on the hinge pin side to fit the rear trunnion then fill the old rivet holes and rivet In the new trunnion. Probably be easier just to buy a new receiver