This is a semi-auto knex gun with what i think is a new triger mecanisam.

You need lots of rubber bands and a quite a lot of knex.

my one fires 2 dark blue rods at a time even though it only has 1 barrel (i dont know why it does that)

Please feal free to use any ideas from this gun as you like and if i have used any thing from any outher peoples guns (because i have made a lot of instructables) then i thank you very much.

If the triger is not a new design then sorry for saying it is new.

it fires around 20feat, this is the first knex gun i have made without istructions so please do not be harsh with coments.

Step 1: Make Sholder Rest

make 3 of first image(1)then add wight clip and put all 3 together(2)add grey clip(3) sorry this part is not very good. ignore the bits in the background on image 2!

Step 2: Construct Firing Pin

this is an easy one just make it(the long rod is grey not tan).

Step 3: Make Triger, Front Handle and Back Handle .

1.make top.
2.make back handle
3,4.make triger
5.make front handle
6.atach triger to back handle.
7.atach front handle to triger.
8.put top on triger (for this you need to small rubber bands of the same size) also the wight rods are NOT pushed in to the wight clips they are just resting(the rubber bands are to stop it falling of), the yellow note box is just to show where i mean.
9. put rest on back handle (using a dark blue rod and 2 tan clips to hold grey clip(for grey clip see step 1 image 3)).

Back of gun now done!

Step 4: Make Barrle

1. make the 3 bits
2.join like so...
3.make these 3 bits...
4.put them on...

Step 5: Make Auto Load System

1. make 2 side panels and 2 end panels...
2 but actualy seen on pic 3.add them to the barrle
3 but seen in pic2.build ram and "small thing"
4 seen in pic 3.add ram + 1 rubber band
5 seen in pic 4.add "small thing"

sorry about this one, the images are all mixed up.

Step 6: Make Stand

1.do whats in the image, oh and the wight rod nearst the end of the barle (near the amo store needs to be changed to a dark blue rod).
2. make sure you have changed wight rod to dark blue then put the stand on.
3.you can fold the stand back if you need to by sliting it in to the "small thing" see image.

Step 7: Put in Firing Pin

1.When you put the pin in lift the ram up or the firing pin will 'BREAK' the ram as you push it through!

Step 8: Put Front on Back

title says it all!

Step 9: Add Rubber Bands

1. if you can not see what to do in image please just coment
2.i have only used 1 rubber band so it is easyer to see but you can add more,(if you add to many it will break the firing pin and you can not put tape on it or the triger will not lock, this is the bigest proble with the gun).

Step 10: Load and Fire!

1. to load lift the ram right out and put 4-8 dark blue rods in(as it fires 2 at a time the amount you put in must be even).
2. to fire you need to pull the triger right back, if the "top" falls of then make the rubber bands stronger or decrease the power of the firing pin (adding more rubber bands to the "top" can make it harder to load).
3.the orange clip of the "top" can stop the orange clip of the firing pin (the one on the end of the dark blue rod) cliping in between the yellow and the green clip, if this happens lift the back of the orange clip of the "top" slightly ang carry on pushing it through.see image 1.
4.look at image 2 to see the triger proply set.