SR70A1 Precision Sniper Rifle System. Great range, accurate, powerful, versatile, you name it.
It is a ramrod rifle. It uses #64 rubber bands, and looks great.

Also, I have now made a folding bipod for this gun. Now all I need is a hammer/firing pin guide because at 5+ bands, the black rod begins to bend and break. In other words, I need something like the Z35's guide.

Pros
Ramrod rifle
No jams if made correctly
Easy-detach scope and barrels
Smooth True Trigger
Fires any rod
No mags
Any accessory can be attached
Lefty support
Comfortable
Scope with dot sight; accurate.

Cons
May be too small for some people
No mags
Grip may be uncomfortable for big hands
Barrel can droop, but fixed by a rubber band.
Well...that's all I can think of.

-------------------------------------------Notes from the Author--------------------------------------------
Sorry folks, I'm afraid this will be my last work uploaded. This gun, along with the ible, will be an open source for inspiration, upgrades, and new models for the K'nex builders that will follow.

I, Prodo123, hereby grant the right of usage of this Instructable to every individual. I also grant the right to use the name "SR70", "SR70A1", "SR70A1 PSRS", "SR70A2", and "SR70A2 PSRS" to every individual whom has upgraded and/or modified this gun. I hereby grant the permission of modification, reproduction, reconstruction, and deviation of this gun, Instructable, name, and video to every individual who does so, for as long as they give credit to the source. I hereby permit the use of this Instructable as inspiration and without credit to every persons interested. Those who do not comply with this permission grant will be reported and/or dishonored, and is not limited to a ban, a suspension, and/or the deletion of the Instructable. I, Prodo123, grant all of these rights, and the consequences that follow, to all individuals.

Long story short, you may use this Instructable to modify your SR70A1 PSRS, SR70, or create a new model/variation of the gun, for as long as you give me, Prodo123, credit.

Also, you may use this Instructable as inspiration, and you may do so without giving me credit (If you do give me credit, I give you a cookie :3)

It's been a good time here at Instructables.com. I'll hang around, but sorry, no more K'nex for me.
-Prodo123-

Step 1: Butt, Grip, Trigger, and Faceguard.

Tailored for me. Might not fit you, but I would assume it would. It's really comfortable. I would guess that people would ask why is the butt empty? There used to be a monopod there, but it was useless and I got rid of it.

Step 2: Barrel Part 1 - Firing Chamber

This is where the magic happens - where the hammer hits the transfer rod. Also includes additional faceguard, scope mount, hammer, and rubber bands. This step takes for granted that everything you do is SYMMETRICAL. which means what you do to the left, you do to the right.

Step 3: Barrel Part 2 - Transfer Rods

The heart of this gun are the transfer rods. They're like floating hammers, or the balls in the middle of a Newton's cradle. All they do is transfer the force of the hammer to the bullet, which goes FLYING. This step takes for granted that everything you do is SYMMETRICAL. which means what you do to the left, you do to the right.

Without this section of the barrel, the gun will NOT FIRE. This is necessary, do not skip any step on this part or you will get broken pieces or a non-functioning gun.

Step 4: Barrel Part 3 - Bullet Housing and Assembly of the Whole Barrel

This is where the bullet goes in. Many people get confused where it goes, it's a muzzle-loader, not a breech-loader.

Step 5: Body

The cross between a solid and a flexi-body from SR70 is this. Super comfortable while extremely sturdy.

Step 6: PST-70 Scope

Precision Sniper's Tool PST-70 scope. Dot sight. You can put other scopes on, but I recommend this.

My new Quick-Detach, Non-Zero-Disturbing, Angular-Mount mounting system. Angled so that it looks straight at the iron sight for maximum accuracy, while being really easy to take off to use the sights itself. The mount is fixed by tan connectors on the barrel, so the rod doesn't move around when you look at the scope. The only downside is the dot is sorta out of focus, either you look at the target or you look at the scope, but the dot is optional.

How to attach the PST-70
1. Insert white rod on the end of the scope into the end of the mount, in the gray connector.
2. Clip on the Y-connector to its corresponding location.
3. Push the gray rod all the way forward until you can't push it in anymore.
That's it, easy and simple.

Step 7: Assembly!

FINALLY! You have made all the parts, now t o put em together.

Step 8: DONE! How to Load and Fire

A. Pull the hammer back. It should be easy, especially with the new handle.
B. The trigger should pop up into the slot, effectively and smoothly blocking the hammer. If it doesn't, push it up.
C. Put ammo in at the MUZZLE. That's the END of the barrel. Recommended ammo is yellow rods, red rods, and blue rods, but it will accept any type of ammo, either with a filler or a pusher rod. I personally prefer yellow and red rods, either without tip or with a Oodammo-type tip or a ball bearing tip.
D. Aim and fire. Not that hard.

If that was too hard for you, here's a video on how to do it.

The video has an experimental bipod, similar to the one on the Galil Marksman's Rifle. Some tips would be nice.

Future accessories to come. Send me pics of your finished guns, I will post them. If you have an idea for the bipods, PLEASE TELL ME!

Pic 1: Beta Prototype
Pic 2: MOD-A Prototype
Pic 3: Mberg's SR70A1 PSRS
Pic 4: Prodo123's SR70A1 PSRS, with prototype bipod and mount rail