3D Printing Adventures: Upgrading The NiteScout A3

I’ll keep this one short but sweet. My readers may recall my review of the NiteScout A3, and some various caveats I had about it. Believe it or not, I still rather enjoy the rifle in its SBR form, and have been trying to figure out how to give it a modern handguard. The handguard that came on the A3 could charitably be described as heavy and obsolete.

When I was looking at pictures online of various MP5 handguards, I was struck by the realization that they looked rather similar to the A3 handguards in how they attached. Rolling the dice, I bought a PTR-9 aluminum handguard to see if I could fit it.

Shockingly, it screwed straight into the retainer. But this left me with a problem: the tube that protects the screw connecting the front sight to the receiver was too long, and so was the screw.

Enter my 3D printer! A bit of OpenSCAD coding and a couple of test runs netted me a tube that fit just right. After a quick run to Home Depot for the correct screw (1/4-20 coarse, 3″ long), I had my handguard adapter all ready to go

The original part was aluminum, so the plastic replacement is not necessarily as robust. But there’s really no weight bearing component to this, and all of the pressure is directed into compressing the layers. Even a tube with somewhat small infill is more than enough to do this job.

I am genuinely stunned that NiteScout didn’t just outfit these guns with MP5 and MP5K handguards right out the gate. It would not surprise me at all if you could put on a MP5K handguard with either no tube or a very short one. But, in any event, I managed to fix this problem on my own. Next stop: Magpul SL grip and safety…

I ran the gun hard last night at SASP practice, and the 3D printed part seemed to hold up just fine. No problems with heat damage were observed. The gun itself isn’t really a Steel Challenge champ (that long, heavy trigger!), but it is super reliable, which is not nothing.

ETA (9/6/2021): The Magpul HK94 safety works quite well with the gun. The SL grip… not so much. Even after shaving down the back of it to be flush with the receiver, the gun still refused to fire when I dropped the hammer. I assume there is some sort of tolerance issue with how the hammer is positioned with regards to the bolt, but have not had time to track it down.

9 thoughts on “3D Printing Adventures: Upgrading The NiteScout A3”

  1. Looks awesome, good job! I’ve got an A3 carbine on the way to my FFL at the moment, I picked up an HK wide handguard to put on it and i’m certain i’ll run into the same problem. I’d gladly pay you to print me one of those, if you’re interested shoot me an email.


    1. Even if you could just send me the file for it I could probably have somebody locally print it in aluminum. If not its no big deal, it’d just save me from a world of headaches trying to fabricate something.


      1. Hey, no problem man thanks for following up. Since then I did some research and realized that an Hk53 handguard will fit perfectly with the stock tube (I had to make some bushings to keep the back of it tight but now it’s totally solid). If you still have that file handy though I’d definitely still like to have it just in case I decide to switch to the MP5 handguard I originally bought once I get it stamped as an SBR someday. Thanks again man

        Liked by 1 person

  2. Awesome work, I’m working on bringing these back to market. I’ve got those tubes, I’m sure I could get one cut down if your interested let me know.

    Liked by 1 person

  3. Yeah I put the Magpul safety on mine as well, I’m a lefty so it’s a big help. That’s interesting the grip module is giving you problems, seems like it should work fine as long as its the same trigger group and stuff, but who knows. I almost got one for mine but decided against it at the last second. I wonder if Magpul’s MP5 SL stock would fit on the NS receiver, I doubt it would though without unsightly modifications since I don’t think the NS endcap is the same as the MP5 one. How did you mount the stock on yours? ACE stock adapter or something? Mines got the UMP style aluminum one that some of them came with, I’ll stick with that unless I can put an MP5 A3 style one on it somehow.


    1. I also thought the grip module was gonna be no big deal, but it definitely required modification to fit at all, and the hammer did not seem to hit the firing pin when I pulled the trigger. Clearly, there were slight dimensional differences, which was also intimated to me by a contact who’s trying to bring these guns back into production.

      The MP5 stocks are flat-out not gonna fit. I used an ACE adapter on my NS A3. It is possible that LUSA stocks fit.


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