Removing the stock RIS from Ares AM-13

[skillfulmmd]

Does anyone that owns the AM-13 or AM-14 know how to do this as the only video I've seen online just says to remove one screw and it should slide off. Mine however, no matter how hard I pull won't budge and I don't want to break it trying to take it off.

 

[skillfulmmd]

Solved it one of the rails on there was pushing against the mock silencer I loosened the screw and jobs a gooden.