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EMG x Retro Arms CNC Machined Aluminum Rotary Hop-Up Unit for M4/M16 Series Airsoft AEGs

5 Customer Reviews

by Kevin C. on 11/01/2021
"Make sure to not over tighten the circular silver screw near the bucking on the front of the unit. If you do your gun will misfeed or jam because the inner barrel will be too tight.
by Bill S. on 06/18/2021
"great hopup unit. few modifications were needed to my maple leaf rubber, the lips were a bit too far out to the point where the bbs dont feed up. i had one flaw with this, if you use the inner barrel secure nut with a 5KU outer barrel, the hop unit will not be able to be pushed forward enough. luckily you are able to use a regular brass ring that comes in a stock hop unit and it will be pushed forward enough. this hop unit comes with everything needed to install it except it has no spring included to be pressed against the outer barrel. you will need to use one from your stock hop. you also have an option to have an o ring at the bottom of the feed tube to stop bbs from falling out. the o ring is included
by Chris V. on 01/21/2021
"I put this with the Angels Custom 6.03 barrel and it is shooting great the hop up is very sturdy and sensitive at the same time (which I love). I recommend this for anyone trying to upgrade their gun. 10/10
by Nidal J. on 10/06/2021
"Overall, it is a nice hop up, and it works great with a Prometheus barrel and Prometheus purple bucking. However, it is machined poorly and had metal bits around the cuts for the o-ring cut-off. They were easy to remove with some needle nose pliers though. I decided to try this because of the cheap price, but I am still going to stick with my favorite Maxx ME Pro hop up units.
by Zachary N. on 01/22/2021
"Keep in mind these are designed for the Retro Arms outer barrel lug. Though it can work for other TM spec M4 outer barrels it works best inside a Retro Arms outer barrel attached to a Retro Arms upper as the specs are slightly different than most TM spec M4s. I dont really understand why EMG did the endorsement since almost no one runs full retro arms M4s because the body parts are Very expensive and sort of proprietary. Retro arms has High quality parts for sure but look out for their beautiful outer barrels and hop chambers not working well without each other.