About: K'NEX gun builder here at Instructables. More or less retired from the community, but I still pop in now and again.

Out of the hundreds of different assault rifles there are out there, the ARX-160 has long been my favorite. Having been attempted by both Blue Mullet and KnexBuild, the ARX-160 was no easy build. In the first place, the distance from the bottom of the mag well to the top of the receiver is 5 1/2 in. It took me a year and a half to get the measurements, and I got them at a gun show some months back. This replica is full size, coming in at 32 in. long (a standard size for most assault rifles nowadays), and it weights between 2 and 3 lbs. The magazine has a good capacity of 16 rounds +.


  • 16+ magazine capacity
  • 32 in. long
  • Sturdy
  • Great range: 60 - 80 ft.
  • Great pin pull length: 7 - 7 1/2 in.
  • Super modular
  • Great sights
  • Nice stock (if you have the time and the pieces, it would be really easy to make it a telescoping stock)
  • Super usable (It might even work in an indoor K'NEX war)

This is my first entry into the Toy Rods and Connectors Contest, so don't forget to vote for my entries!

-The Red Book of Westmarch



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    21 Discussions


    5 months ago

    Awesome! That gun doesn’t look like over a 1000 pieces. More like 100 or 200.

    War pig

    4 years ago

    That looks sweet!

    First off, this gun looks amazing. Regardless of the mech, this gun is awesome just because it looks so realistic.

    However, I do want to know how you got a 7 - 7.5 inch pull. Just think about it. A black rod is only 7.5 inches and the end part is 5/16 inches (I measured), and you have to leave at least 1/4 inches (usually more like 1/2 inches) of the rod sticking into the barrel so it stays in place. Also consider the 1/16'' or more consumed by the rubber bands/tape on the end of the pin. So best case scenario, 7.5 - 5/16 - 1/4 - 1/16 = 6.875'' So realistically 7 inches is nearly impossible to achieve. 6.5 - 7 inches is more believable but still very good.

    2 replies

    Thanks man! I am so glad you like it! I was hoping it'd get more attention than it did, partly because it is the ARX-160, and partly because it turned out so well (better than I expected). Don't forget to vote for my entries in the contest! My bro could use some votes as well (his name is E Plruibus Unum)!

    Well, I may have been slightly exaggerating, but I believe I said that I got between 7 and 7 1/2 inches. Maybe a little less, maybe a little more, but about that long. I understand that you think that is more or less unrealistic, but the mech that this gun utilizes was strongly setup, and powerful enough to get that type of pin-pull. Besides, the hybrid-pin (completely original BTW) that I was using allows for as much pin-pull on most guns as possible.

    Thanks for your support bro, check me out on Google + to see more!


    4 years ago

    I'd agree with Aug, but its a replica and that's all this gun is about. Huge, slightly obese power....... No offence to the original gun either =D. Anyway great gun! Very well done!


    4 years ago

    Looks great!