THE ULTIMATE GUIDE TO RAREBREED TRIGGER

I made an effort to purchase a single for a pal, but They're under no circumstances in inventory.  If I am unable to basically click on and buy, I'm not gonna bother.That's what I am pondering.  I have a batch of aero lowers coming in and received a PSA Easter sale on the Construct kit.  Could you run a type of firing pins in the 556?A MP5 trigg