Failed K'NEX Bullpup SMG

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

Hey guys. Well, after BlackShadow12 posted his Failed bullpup knex gun, I thought I would give a try at making a Bullpup. There was only two differences that I wanted: 1) I wanted the mag to go in the top, and 2) I wanted a permanent for-grip. So that is what I did, and it failed (hence the title XD). The Pros and Cons are not entirely impressive:

Looks kinda cool (IMO)
It is a Bullpup
Trigger worked smoothly
New type of mag (I have yet to see a bent mag of that caliber)
It is comfortable
The for-grip was a great idea
The mag can either be set to go in the top, or up the bottom
Was not too piece consuming
Range: 30 - 40 ft.

Did not work
Handles were at a weird grip (I HATE handles at that degree)
Mech needed more room
Fake barrel was lame looking
FP hardly ever hit the bullets
Mech was on the outside

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    52 Discussions


    6 years ago

    Excuse me if I'm wrong but that gun below this post doesn't look like anything special to me, all I see is a breech loading pin pull gun, so why save it for the contest?

    9 replies

    Well, you never know what the contest will be about, and just because the gun does not seem special, does not mean it is not. First off, it is breach loaded, which is something you NEVER see from most other people. Secondly, it gets at least 70 ft.

    ok I guess I don't post much but..... I am pretty good, won't have anything rolling of the presses for about a month or two but, how about you? any great and awesome plans? btw I do plan on making full auto soon, of decent range and with a mag not a belt or turret, it is quite complicated but that's the way I like it. Bolt action will also be made possible soon =P lol and I plan on building a functioning horizontal mag gun, rivaling seleziona's, his didn't quite work like it should, also (I know im going on and on but) I would like to make a decent bullpup gun. I have many ideas but they don't translate well into k'nex for some reason, but I have fun anyways. So like I said earlier do you have any ideas, groundbreaking or not? I have to go now my mom is yelling lol.

    Well, unlike you, I post, even when the thing I have in hand is not that great (for example, the gun above). I don't say that your way is not much the best, but we all have our differences. Any awesome plans? Me? No, not really. I plan on making a better M21/M14, but I have no idea how that will go over. All of the projects you named sound amazing, and I hope to see them from you soon. Making a full auto gun sounds cool, but incredibly hard. A bolt action sounds awesome as well, especially to me. I have made only one bolt action in my life (the S1) and it did not seem to me to be any cooler than a regular pin gun. I have achieved the same type of range with my RMACR as any bolt action might provide. As to the bullpup, I wish you luck. Wow, your mom yells too? Funny. I guess there is no new thing under the sun. =D

    I know I'm replying to an older post, but red.... How is it possible that you got 30-40 feet on a gun that you say 'did not work?' Great Idea as always, though, and I do quite like the looks.

    1 reply

    I can under stand the confusion, so let me explain. This guns was a complete failure, and what I mean by that is the fact that it was nearly impossible to get it to shoot. When it did fire (those one or two times) it got O.K. range. I honestly think it is ugly, but that is just me. Thanks anyway. =D


    6 years ago on Introduction

    It really does baffle me why people struggle so much with bullpups... Sure it's different and requires a bit of different, possibly out-of-the-box, ingenuity, but it's not as complicated as people make it seem. I've built so many bullpups it seems obvious to me, so I'm sorry if I sound arrogant saying this, but I think if you just think a bit more and give it a bit more time, and don't be afraid to learn from past bullpups, take my own as an example (just for my laziness and not updated status), just try and try again, and I'm sure you'll get it eventually... Whatever, I'm just saying that whenever I was building new concepts or complicated designs I could work for weeks on a single area until it was perfect. Concepts and complicated designs aren't easy, but if you're dedicated and think and do your homework, I'm sure you could figure it out...

    5 replies

    That is true. Many people make Bullpups look harder than they truly are, but then again, they are much more complicated (and this is necessarily so) than any gun that has the mech and mag in front of the handle. Part of the reason that I chose to give up this gun is because I wanted to build other stuff, plus, this gun was just not appealing to me any more. Plus, I chose not to spend too much time on a gun. If a gun is taking longer than one week to figure out, I generally just stop. Besides, Bullpups require many unwanted byproducts...

    The only main complication is the trigger, nothing else, and I myself have found and demonstrated several ways of bypassing this problem and there are many more solutions other people have made... Whatever if you're not gonna put time in it, chances are, it's not gonna be good...