Here it is. My yellow rod mag fed Battle sniper. It was built with large scale multiple floor knex wars in mind, and just nicely, fits that purpose very nicely.

The Storm 221 incorporates a new size magazine which is just outside the width of a yellow rod, minimising Magazine friction from the old design. The mag is sadly not removeable, but makes up for this in the fact that there is hardly any trouble whatsoever in transition from mag to mag well.

This shoots about 95 ft with 3 rubberbands, one on its own and the others tied together. I couldn't try with more on, because I'm using them on my *gasp* secret project! No sneak previews yet, but you'll see when it gets posted.

Its accuracy is very good too. From a range of 30 ft, I can hit a cardboard target that is about 50cm² almost all the time.

Version History:

V1.0 I rebuilt the 221 again with hopes of making a V2.
V2.0 Ok, I Added a magazine, like the one in the 220 V2. It fired significantly shorter distance. I didn't like this. (Jamalam cat is NOT amused)
V2.1 I modded the mag well to have less friction and more power. It worked out better, but for a sniper, I decided that 40 ft was not enough.
V2.2 I decided at this point to build it a new body, which worked out great, but for some reason after this the range was lowered by over 12 ft. I still have no idea why. Between this version and the V2.3, I managed to fire it and blow up the mag, destroying an orange connector :(. Yerjoking, this was the version I showed you on MSN, and the pics are in the intro for everyone else.
V2.3 I wanted the range back to proper standards. I started on a new mag design using green rod horizontal intervals instead of white rod horizontal intervals. For this to work, I also modded the mag well. This, I found, shot 95 ft. I am happy!
V2.4 I just made some minor touch ups to the looks, added a bipod, and posted here!

Pro's
Range of 90 ft.
Accuracy to within 25 cm off target from 30 ft.
Bipod
Has yet to jam, the bullet always leaves the barrel.

No's.
When you move fast, you can't aim at all.
Hurts when it hits you.

This is good in war situations, because you can snipe from many angles. It is slightly lighter than the 220 V2 - which was built more to scare people witless in a war situation because of its hugely unnecessary bulk - which allows this to be fast aimable and more agile so you can run for cover. I love it. I haven't tried it out just yet, but I might show you a quick war video when i get friends round.

War gun - Primary - 4/5. It has a reasonably large magazine, but not enough to hold out very long. Because it is not removeable, each of the yellow rods have to be loaded in separately, or else in a clip with a post it note on the side. The power is great for primary, and this should be formidable.
War gun - Secondary - 5/5. The storm 221 V2 has incredible range for a mag fed gun. If you go to a window, in a tree, or on the ground with a bipod, you are sure to be a formidable enemy. I would use this as a secondary.
General - 5/5. I love it. I just play with it all the time.

You like this? Let's get building this beast, shall we?

EDIT: after i got #64 rubberbands, the proper range is 60 ft max.

Step 1: Handle, Trigger, Stock and Firing Pin.

This is a large step, so pay attention to the pictures and check what you are doing.
1) Build this part.
2) Close up on Firing pin.
3) Build this part too (sorry about the shadow).
4) Add these to part 3.
5) Build these parts as well.
6) Add them to Part 3
7) Complete the stock, and build the part in the corner.
8) Add this on to complete the step.

Step 2: Body and Barrel, Part 1.

In this step, you will Build all of the necessary parts that will go inside of the gun to fire it.
1) Build this twice, one without the orange connectors or bluerods.
2) Build these 3, and get a green rod.
3)Put this on now to save complications.
4-7)Build this. Hopefully you can see what is going on.
8-9)Build this too,
10)Put it on!
11)Build this.
12)Build the noted bars.
13)Attach grip
14) Build the barrel. When you put it in, you can put spacers on, but they aren't needed.
15) Finish by adding the barrel and the sight top.

Step 3: Body and Barrel, Part 2.

Just put the side on the thing you have just built.

Step 4: Connecting the Halves.

Here, you will have the majority of the gun finished. Good luck!

Step 5: Bipod (optional).

Build all you see in the pictures. I found out, if you replace the orange connectors that connect the bipod mount to the grip with hinge connectors, you can fold this in to keep it compact. This is purely optional, you don't need to build this if you don't want to.
1)Build the Bipod Base.
2)Attach to the main gun.
3)Build this too.
4)Complete the Bipod.
To work the bipod, Move the yellow connector with the green rod on it up to close it, and down to open it. Have fun for a while, looking at this amazingly awesome device. Then, remember there is still one step to go. Keep going for about... 5 minutes more, then proceed.

Step 6: Banding the Gun, Loading and Firing.

Collect the rubberbands in the picture. There should also be a small thin one there, but you can't see it. Put the rubberbands where you see them in the picture.

I almost forgot, put this blue rod into the gun behind the sights for strength... I forgot to put it in, lol

.To load the gun, place some yellow rods in the magazine. I find that about 5-7 work best, but I wouldn't do more than that, because the mag pusher will bend and break.

Then, pull the firing pin on the right side of the gun back. The trigger should lock, and the magazine pusher will go up a bit. Pull the trigger, and watch the mayhem take place!

Thanks for looking at my instructable, and building my gun if you did, good luck and have fun with the gun!
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(o.o)
(> <)
The Jamalam