Credit to Gorkem for the butt shape, Jager for the trigger and the end of the barrel, and the inventor of the OSNJCKMA2 for the adapted magazine of his that I extensively adapted for my gun.
XKR stands for two things - Xtra-good Knex Rifle, or eX Kevin Rudd, our new jerk of a Prime Minister.
I am not going to state a range, because it is impossible to measure a range, because people have different elastics, and build it differently. What I will say it that it is quite powerful, and with one elastic on each side of the ram it fired as far the Gorkem's sniper I built. Maybe I did a crap job with Gorkem's, or maybe this is really good. I dunno.
Parts List (all counts are approximate, but they are pretty accurate)
9 Grey rods
1 black rod (or grey if you don't have)
6 purple/green bendy rods (just decorations)
6 red rods
1 tan rod (or red, if you don't have)
13 Yellow rods
39 Blue rods (or so - they're hard to count)
Lots and Lots of white and green rods
Lots of light and dark grey connectors, most of them are intercahngeable
30 reds (plus six on front handle, or something else)
42 yellow connectors
49 full circle connectors - all but 4 can be swapped for 7 slot ones.
36 straight connectors
42 green connectors
P.S whenever I say "magazine", what I mean is hopper, but my ego gets that much bigger when I say that I build a magazine, rather than I built a hopper.
Step 1: The Butt
1. How it will look when it is finished.
2. Build this. It actually faces the other way round in the gun.
3. This is the ram.
4. Attach them together like this. Don't forget to add the brown connector.
5. Now add two rods on top, and a yellow connector below them.
6. Add another grey rod through the red rod, and attach the two green connectors.
8. Attach this. The only point of connection with the rest is the horizontal blue rod.
9. When building this, attach grey rods to red connectors and then attach it to the blue circle.
11. I only had one bendy yellow rod left. If you don't have them, a pair of normal ones will be fine.
12. This is slightly more difficult, but just follow the picture and you can build this butt. This is copied almost exactly off gorkem's sniper, so credit to him for the shape.
Step 2: Trigger Block
1. Build this. There is an error - the green connector in the top right should be clicked into the slot above it.
2. Add this. The second group of blue connectors is swinging to show you the best way to add them - brown connector first, then add the blue connectors swinging, then press green rods in to hold it in place, as shown in three.
3. Remember to have blue rods on the bottom of the blue connectors, and the white rod on top.
4. This is at the bottom. The purple rods are just decoration - they aren't necessary.
5. These are the components of the trigger. build them.
6. This is where the trigger bits attach on.
7. This stuff is for strengthening.
8. Build this. I would do it in detail, but some of my pictures have gone AWOL. Just remember that this is symmetrical.
Step 3: Barrel and Handle
1. Build this. It is upside down. The hot pink connectors are not supposed to be there - replace them with two blue spacers.
2. This is a bit indistinct. In the bottom right, the black clip is on the far yellow rod, and in the bottom left, the grey 3D connector is NOT actually clipped onto the white rod, it is just touching it, really.
4. Remember how I suggested building the blue/brown sections before. That's why the last one is swinging. You should attach it to the rest.
5. Build this. It's the front handle. The red connectors can be dark or light grey.
6. Attach to two together.
7. Create this section. It is ADVISABLE, but not necessary, to use light grey connectors.
8. Now attach the top part on.
9. Now attach your two big parts together. The large green lump at the top needs to be taken off to put the two bits together, but attach it back on again afterwards.
10. There are actually two red rods, but you cannot see the one on the other side.
12. Add it into the handle, along with the bits at the bottom of it.
Step 4: The Magazine
1. Just build the magazine shown in the picture. You don't need sticky tape around the white rod, but I found it keeps the sides slightly more apart and lets rods slip down more easily.
2. These two yellow connectors keep the bullet lined up in the magazine. Make it and set it aside for later.
Step 5: Puit It All Together!!
1. Finished thing on top, all the parts of your gun on the bottom, plus some pieces you need to put it together.
2. Attach the butt to the trigger block. The green rod on top is just decoration, and it should be purple. However, I find it makes the shape flow better.
3. Attach the barrel + handle section to the trigger block. It is quite tricky, but persist and you will get there.
4. Add the magazine in. It is a stripped down version that I made because I ran out of pieces, but it is a good example of improvising - my favourite K'nexing word.
5. Add in that bit you made along with the magazine. It is only attached on on the opposite side in theis picture, but I only did that so I could get it in, and to show you how it worked. You should attach it on this side too.
6. Another rod you can put across the top of the gun, again just to make the shape flow. It would ideally be purple, but I ran out of them.
7. This purple rod is across the top of the barrel. You have to take off one of the green connectors to get it to attach on.
8. I thought putting this purple rod along the bottom of the handle and barrel was particularly clever of me. I invented a whole new way of holding K'nex pieces in on the handle, too.
9. Well there you go! This is the finished gun, with the elastics on and the gun cocked. I hope you enjoy killing all of the n00bish K'nexers out there with your exorbitantly good rifle.