i bought 2 of these for my echo 1 M16A4 at first i though that they were way to big but with some fiddling i got them into my gun.
one of them fit and the mag lock clicked but the second would not click but all you need to do to fix that is to just fill off a small amount of the metal off the top of the hole were the mag locks at it real easy
now they both fit nice and tight after putting them in and taking them out a couple of times they fit a lot better
they have a real nice finish to them most of the paint on the mag that came with my m16 have rubed off but not on these there still as fresh as the day i bought them
fit nice (after some fiddling)
need to file some of them
Rating: [5 of 5 Stars!]