Halo MA5C assault rifle AIRSOFT CONVERSION pic heavy


Hey guys. This is the first real time I've been here. I've been working on my Halo 3 spartan armor, but I figured I'll post this now just to show that there is one in the making that will actually look like the real thing and not some cruddy, distorted famas thing. Well, basically, I'm taking a P90, gutting it, and putting the internals inside of the assault rifle kit from Justinian, and adding the ammo counter kit from thatdecade. This is where I've gotten in the past couple of days.

The upper has been notched out so access is granted to the inside. The buttstock has been ground out with a dremmel (will need some refining). The P90 has been gutted, and the high cap has been modified to be smaller (will need additional modification before seating). Going to try and get this done by the 17th because I have a game that day and I plan on unveiling it then. Hope you enjoy!





First time the two parts fit together with the gearbox inside

Here it is seated in


The hollowed out buttstock

my photostream if the pics don't properly upload




New Member
This is interesting, I was just thinking of this the other day. I'll wait and see how yours turns out.


Jr Member
Very awesome, are you going to make the mag for the AR the actual mag for the gun? I was going to do a similar build with a DMR and use the internals of an AUG so the mag
for the AR can be used for loading bbs.


Very awesome, are you going to make the mag for the AR the actual mag for the gun? I was going to do a similar build with a DMR and use the internals of an AUG so the mag
for the AR can be used for loading bbs.
The mag won't fit. The buttstock is actually fiarly short (the gearbox sits only a couple of inches above the bottom of the gun. I'll end up having to custom-modify a (or a couple into one) P90 magazine to feed it through the receiver. It's too skinny to fit a full sized P90 magazine in it, and the stripped-down version is still pretty thick. So I guess your answer is no. I thought about making the DMR as well, but Justinian had a very detailed and awesome kit for the AR that I just had to fit the internals into. I would watch out for the gearbox size in the AUG. They're bigger than they seam, and with the hopup, fitting a magazine may not be in the right spot (or possible). So far this is going to be the first airsoft conversion that I've seen where the gun will turn out looking just like the real thing. I've seen other ones that are airsoft, but they are distorted and ugly.


New Member
Looks good so far, Im just wondering how you plan on cooling the motor, unless you cut vents, heat will be a problem.


I've always wanted to do a build like this but I planned on using the internals from a FAMAS
I believe they're both version 7 gearboxes right? if so, there wouldn't be too much of a difference. The main thing I've seen people do is add to the body of a FAMAS, but it gets all distorted and stuff. I could see doing it to a battle rifle, but I'd have to check sizes. Besides, I've already spent enough money so far. I'll wait a while before I do it. (and I need to save up for the Xbox One haha).

Looks good so far, Im just wondering how you plan on cooling the motor, unless you cut vents, heat will be a problem.
Since the motor isn't going to be constantly running, I'm not too worried about heat (I may widen the slot a little for the motor). The motors that I run in my other guns have never had that problem, and they're completely surrounded in the pistol grip. Thanks for the tip though.


New Member
Very sick build! I've never been confident enough to mount the internals from a gun into a totally new housing, I tend to get a little hung-up on performance to trust my "machining" skills to line everything up optimally. :D

I'll be very interested to see how the magazine situation works out, that's the reason I abandoned the MA5 and went with the BR55 instead.

Also, the FAMAS uses a long-discontinued Version 1 gearbox known for chewing up bevel gears left and right, for which there are no aftermarket replacements. I don't think it uses a standard cylinder head, and I know it doesn't use a standard shell. It's an old design that can't really be upgraded or repaired, so I'd steer clear of it. With a little work, a Steyr AUG makes a gorgeous platform to build many of HALO's weapons on.

I'll be curious to see how sick this thing is when it's done though, I'm really excited.


New updates:

So the trigger has been made and is in place. The spring is secured to it so that there is a resistance allowing it to reset to normal position.

Before mounting, metal tubing was used to create a slip between the mount tube and the trigger posts. The trigger is cut from the P90 trigger.



The mount pipes are secured with epoxy, and the spring with hot glue.



I also finished the wiring for the gearbox, so it now has a trigger switch and the correct battery connectors. I by-passed the origional trigger method of using linkages and a push rod for just the switch. You can see in the photos and videos.




And a couple of update videos:

This looks sick, can't wait to see how it turns out! Does the ammo counter work or is it just for looks?
I hope that answered your question. Haha, but it won't actually count the number of bbs being fired.


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Ok. Couple more photos. Also, I got around to test firing a couple of bbs and it shoots!
I had modified the hopup so the it is inverted from its standard position to feed from the bottom rather than from the top. I also notched out a slit for the hopup to sit in the receiver. I'll post pictures of that later.

The bondo in the pictures is from repairing holes that I made while carving out the stock and to fill the gap for the trigger.





Thats sick dude, good job so far and keep it up! Haha I remember way back when I played airsoft and the v2 gearboxes came out and everyone flipped they were so excited. I wish electronic ammunition counters would become actually more useful than cumbersome in actual firearms. But they aren't... Unless you're super secret squirrel and have some kind of advanced and extremely accurate HUD that does it.... Hmmmm....? Nope. Must stick to one project at a time!