Hey I am planning on using my friends as target practice this weekend and I have a problem!
My hop-up unit is toast!
So, my question is will this fit in my KingArms Colt M4A1 without any problems?
http://www.airsoftparts.ca/store2/in...oducts_id=1582
(Madbull Ultimate Hop-Up M4/M16)
Thanks! Any input about this item is appreciated!