Hello everyone, this is Fidel from NiceAirSoftEquipe and today we’re gonna make a little video on how to install the CNC hop up chamber for M4 manufactured and sold by AirsoftPro. Before installing the new chamber we will use the chrony so you can get an idea of the FPS with the stock chamber.
*Not stable at all – will keep on dropping to 417fps* In the box you’ll find : The chamber itself. A rubber and a spacer. All the gears you’ll need. Some O-rings. 2 springs to make it work. The lever.
A lockpin, a screw and some washers. A C-ring and a ring to keep the barrel in place. It’s very easy to put everything together. Install the smaller spring on the lever. Then put the lever in the chamber, as shown, and add the lockpin.
Once the lockpin is in place, put the spacer in. Make sure not to move the chamber too much or the spacer will fall. You can now put the gears in, starting by this one. Make sure it works. Don’t forget to put a washer on the other side of the gear.
We’ll put the spacer in the chamber later on – it will keep on falling. Now you can install the smaller gear here. Then install the last gear (the tall one) and check for proper movement. Install a washer on the middle gear.
Then put the screw here. Make sure not to screw everything too tight ! There we go, now it’s working quite well. Of course, do not forget to put the last washer on the lockpin. The adjustement is very smooth but not loose, and will not move by itself.
Finally, put the last spring here. Here’s the stock hop of my Dboyi M4 CQB It’s entirely plastic and it just wouldn’t keep the hop settings. Plus, it’s highly inaccurate. Either too much or not enough hop.
Quite difficult to set right ! (impossible actually) So let’s switch the chambers. You can remove this ring from the barrel. There, your M4 will thank you for that ! Remove the stock grease from the barrel *laughters in the background because something just fell on my head :-(* then install the Airsoftpro rubber the usual way.
Then put everything back into the chamber (add some silicon oil for easier installation). Once in place, fix the barrel with the C-ring. And finally, insert this ring, and you’re done ! Of course, if the spring fell, put it back in place.
Now, as for the O-rings. They will give you better airtightness by pushing the chamber from the upper receiver against the gearbox. Add enough so your chamber will not move once installed. Once you’re done, put your replica together.
So, the chamber is installed. The silencer hasn’t been put back on since it’s not useful for testing. Now let’s check the chrony. *For reference, FPS w/stock chamber went from 446 to 421, and down to 417 off camera* Ah, 438 ? Mmm.
..okay, let’s keep on firing. As you can see, very stable speed with a good FPS gain, since we went from an average 420 to a solid average of 435. So for the ones who do not like high FPS replicas : don’t worry, this replica will see a lot of changes soon especially changing the spring for a SP100 in order not to hurt anyone.
A quick conclusion : How easy is it to install : very easy, anyone can do it. You have this video to help you out but you can also find a manual on Airsofpro website. Regarding the rubber, we unfortunately couldn’t test it in game.
but as for the airtightness, which is what I’m looking for, there is a clear improvement over the stock chamber as demonstrated with our chrony test. This chamber is highly recommended by our team 🙂 See you soon for another video, and have fun !