RTMP (Red's Tubular Magazine Pistol) (+ Internal Pics)


Introduction: RTMP (Red's Tubular Magazine Pistol) (+ Internal Pics)

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

Tubular magazine guns have always been a fancy of mine, ever since I got a Henry Lever Action .22 LR for Christmas 2 - 3 years ago. As this is the case, I decided to set out and make one out of K'NEX. The gun you see below is perhaps my 4th - 5th try, and is ultimately my best. It holds 4 round if you decide to use the charging rod, but if you decide not to, it will hold 5. I prefer not to use the CR, as I like to shoot, pull back the FP, put a new bullet into the TM (tubular magazine) (this loads a new bullet into the chamber), fire, then repeat. It is quite comfy and light, but it must be admitted that it is the weirdest way to load a mag that I have ever seen in a K'NEX gun.

Some features of the gun are:
- Great range: 50 - 70 ft.
- Nice looks (IMO)
- Not to big to fit into your pocket
- Weird sights
- Trigger is rather hard to pull

Credit to TD for inspiration.

This gun is almost a cross between a pistol and a SMG, and I am not sure why it termed it to be a pistol, but it really does not matter.

-The Red Book of Westmarch



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    68 Discussions

    Oh so that's why it jams when I use white rods

    I turned it into a rifle can anyone tell me why it is jamming

    15, 4:36 PM.jpg15, 4:36 PM.jpg15, 4:36 PM.jpg15, 4:36 PM.jpg15, 4:36 PM.jpg15, 4:36 PM.jpg

    Making a Spenser rifle with tubeular mag in but stock with internal pusher lever action

    1 reply

    Awesome gun! There's not much to say - slick, good looking, seems to work well - nice! I like it. However, a challenge for you (or anyone else reading this), a challenge that was the last I faced (and conquered quite neatly, in my humble opinion) right before I stopped building. The challenge: Make a magazine similar to this one (btw, it's called horizontal magazine or under-barrel mag, not tubular, but no matter...), but make it modular and therefor able to be as long as you want and carry as many bullets as you want. What I mean is, since the typical approach to this kind of mag is a mag pusher from the front, which is very bad if you ask me, because, A, it sticks out of the front of the gun looking very bad and, B, it limits the length of the magazine to it's length or less, which isn't much. My goal was to make a horizontal, under-barrel magazine that had an internal pusher, not sticking out of anywhere at all (sticking out the bottom a little would be acceptable, but mine wasn't) that worked flawlessly and was therefor modular (what I mean by modular is you could repeat the setup infinitely and it would always work) and so the magazine could carry as many bullets as I wanted to and would look enclosed, slick and just plain awesome. So my challenge then - Make a horizontal, preferably under-barrel magazine that is, by my definition above, modular and therefor able to be as long as need be.

    12 replies

    I made a knex pp-19 bizon which features a real horizontal and round mag, which has an internal pusher and internal ramp. Ituas instructions, so anyone can build it.

    Thank you. I am glad you like it. As to what you call a modular IMP mag, I would have no idea as to where to begin. I think that, although it would not be too hard, it would be truly unnecessary, as this is not really a gun that you would want to shoot repeatedly. Well, the K'NEX community might call the mag a "Horizontal Magazine" or a "Under-barrel Magazine," but that is not the correct term. In real firearms, it is called a tubular magazine, so that is what I called it. I chose not to base my names on what others would do, as many of them are inaccurate.

    For example, you would call a gun that has a rod that pushes a bullet out of the mag and into a separate chamber (while charging the FP) a bolt action mech. I would call it a separate chamber mech, as it is not the true definition of bolt action. EVERY "real" firearm separates out each and every bullet, and not every gun is a bolt action gun.

    I agree with you to some extend, and ironically it makes you incorrect. I guess unless you use a tube barrel for a magazine, it isn't actually tubular. Hence why we just call them horizontal magazines because that's just what they are. They're magazines and they're horizontal. But I do dislike how bolt action stuck. I call it chambering in general. Also, terms like assault rifle, sub-machine guns, etc. have no real use in K'nexing aside from aesthetics naming. Likewise, no gun is actually rifled, so calling a gun a rifle in general is incorrect. But that's all nitpicky crud.

    I took into account that this was not tubular when I said that. Like I said, it's a horizontal, under-barrel magazine, but it's not tubular. Perhaps my wording was a bit iffy... I have no problem with 'bolt action' per se, but I do remember being cautious about not calling that gun I made based on your concept (TDAC, if you remember) a bolt action but rather an auto-chambering mech. Like I said somewhere here, I agree that knex guns' terminology as we've developed it is widely incorrect, but then again, as you said, it's all just nitpick crud.

    I wasn't sure if you realized but by comment was directed at red book. Anywho, I decided I'll show a concept for a removable, internal pusher, horizontal magazine I had a while ago when I was hoping it would be used in a P90. It's horribly flawed in many ways as it was meant more for the aesthetic appeal. It held only a limited number of rounds, green rods at that. And then the feeding system was never finished. I had it so the green rods would be locked against the ramp, ready to fall and be loaded if the pusher pressure was taken off, but otherwise they wouldn't load automatically.
    I guess you could make it much longer for a larger capacity. It's just hiding the mag pusher in the magazine itself. But I'm thinking up ideas now for a new weapon with a functional horizontal magazine. I really want to make a weapon that's both easy so I can get back in the swing of things but innovative enough that people would like to see it.


    No I didn't realize you were replying to Red, I didn't notice they added the 'in reply to' thing and without that it's just a big mess of comments... Sorry, my bad. Cool concept mag though, I might give that concept some thought...

    I can see why you would think that, but the fact remains the same. You see, it would be called a tubular magazine because it is "tubular" and it is underneath the barrel. Well, the reason why I term my stuff "SMGs" "ARs" etc. is because if they were to be real firearms, that is what they would be called. Like I said, I like to term stuff to be as accurate to the real world as possible.

    I'm sorry (yes, this time I realize your comment isn't a reply to me, but still), but I have to say something... First of all, I don't think you quite understood what I meant in my original comment... It's not that I'm saying the term "tubular magazine" is completely wrong, I'm just saying that this isn't one of them... A tubular magazine is an actual tube, like most real firearms with that type of mag, however, unless you make it an actual round tube, which is only possible with the use of a line of connectors, it's not tubular. This magazine isn't tubular. I also simply suggested a few other terms, not necessarily "IRL accurate", but still applicable and acceptable that would be more accurate than "tubular magazine", as they do actually fit the description of the magazine. Also, I must say, if you think that real life firearms are categorized in certain ways just based on their size or the way they look (which is the only way to judge a knex gun in comparison with real life firearms), you are quite wrong. The essential problem is the assumption that you can just say "If my knex gun was a real gun...". You can't. It's not a real gun and the two don't function even slightly similarly, so there is no way to compare except for, like I said, looks and size. Guns are categorized according to their functionality aspects such as maneuverability, accuracy, RoF, effective range, round type etc. etc... You can't compare any of these things to a knex gun's counterparts as they are not even mildly similar... You say you like to term stuff as accurate to the real world as possible, but excuse me, that's really not that accurate...

    Now, don't take this the wrong way, of course, this is all a friendly conversation, mixed with a little bit of nerd rage *wink wink*, and I intend no harm. But SHAPE UP! ;)

    Well, I am a bit to lazy to reply in full but I will reply in short. I would agree that you could call it whatever, but this is just something I do. I could have called it an under the barrel magazine, but I just chose not to. =D I would agree with most of what you said, but I am just to lazy to reply.