Introduction: The Guide to K’nex Ammunition

About: I’m no very active here anymore but I sometimes check in.

Ever since the instructable titled “Basic K’nex Cannon” was published around 14 years ago, instructables has been flooded with K’nex guns. Barely any are posted now but I’m determined to change that, without dumb kids posting crappy block triggers. The world of K’nex ammunition can be quite confusing at times so I’ve made this guide to help. Please feel free to let me know of anything I’ve missed and I’ll change this instructable accordingly.

Most of the testing has been done with a TR8-2018. Some of the testing has been done with basic pistols. The testing for “shotgunning” pieces was done with a TR8-2020 with a shotgun turret.

Please not that these are the results that I got and yours might vary. Seeing as this was made in under 6 hours including testing, I might have missed something. I intend to publish more precise results and possibly videos once the weather improves so don’t think I’m finished with this one yet! Some of these are just estimates or guesses for now.

I haven’t posted an instructable for around 6 months now and I’ll try to be more active!


Working K’nex gun and ammunition of your choice.

Step 1: Rods

Rods are the most common projectile fired from K’nex guns. They tend to start to spin out after around 60 feet depending on the gun and wind. Yellow and red rods are the best and most commonly used as projectiles.

Green rods are fine for around 15-20 feet but they are so small that they usually can’t shoot beyond 30 feet or so from a pocket gun. They are generally used in magazine fed pocket pistols or are fired in groups from shotguns. I prefer BB’s from a shotgun turret TR8 but then it’s not really a K’nex gun. Fired from a shotgun TR8, they can go anywhere from 50 to 80 feet while being effective to roughly 40. When used in a shotgun that is fast to reload, they make excellent projectiles for indoors or short to medium ranges outdoors.

White rods are also good in turret shotguns, they can potentially shoot 75 feet. When used like this, think of them as larger shot in a real shotgun; hits harder, goes farther, spreads less, but fewer projectiles and lower hit probability. When used in anything other than a shotgun, white rods are not the best choice at all as they generally go no further than 40 feet.

Blue rods are generally the largest rod for shotgun use and fly farther than green or white rods. When in more conventional K’nex guns, blue rods tend to perform okay with a maximum range (that I’ve gotten anyway) of around 70 feet. I would not recommend these in a war except with a good shotgun.

Yellow rods are better than blue rods for use in magazine fed guns, most notably the ZKAR and its variants. Shotgun use is not recommended because two inaccurate projectiles are inferior to one accurate projectile. I’ve achieved ranges of 50 and occasionally 60 feet with a ZKAR chambered for yellow rods. I don’t really like the ZKAR much because of its lack of range. It’s ok for indoors and CQC and it’s a good secondary. Yellow rods are fine but just don’t expect to snipe anyone as they begin to spin out after 50 feet or so.

Red rods are in my opinion, the best (plain) rods to use as projectiles. They can go 80 to sometimes 90 feet without wind. They are effective to 60 feet or so.

Grey rods are similar to red rods but worse overall.

Step 2: Connectors

Connector are very rarely used as projectiles in good K’nex guns because they are put simply, terrible projectiles. I’ve launcher all of the types of connectors that I have from modified slingshot and pin K’nex guns and never hit ranges over 45 feet.

The best out of all of them would be grey/purple one slot connectors. These are suitable for use in a small pistol (an oodammo pistol of similar dimensions will serve you much better) or just or messing around indoors. There is a shotgun by (I think) Smashpoe that can be loaded with grey connectors for a birdshot effect. If modded to be made stronger, it works well for clearing rooms or just having fun indoors despite the reload time. Not suitable for outdoor or large-scale wars. From a shotgun, they go a maximum of 20 feet, and from a pistol they can go about 30.

Blue caps can also be used as projectiles but they are worse than grey connectors. The guns that fire them tend to be either replicas of real firearms, or pocket pistols. One advantage caps and other small projectiles have is if they start to flip end over end, they aren’t gonna spin out like longer projectiles would. These can hit around 30 feet.

Step 3: Special Ammunition, AKA "The Good Kind"

Special ammunition is ammunition that either requires more than one K’nex piece or materials that aren’t K’nex. Special ammunition (if built and used correctly) will almost always outperform basic ammo.

Oodammo is a type of ammunition invented by Oodalumps consisting of a red connector and a white rod. It is the most accurate “pure” K’nex ammunition. It can be used in all manners of guns including but not limited to; turret guns without too many bands, scaled down NAR’s, magazine fed pistols, and sometimes slingshots. Oodammo is very small which makes it ideal for carry a large amount and this also means that magazine fed oodammo guns needn’t use too much space for the magazine. I prefer using oodammo in my sidearm or even my main sometimes. My favourite oodammo gun is TheDunkis’s Oodassault 3.10. Oodammo can shoot about 100 feet from a TR8. The only thing I don’t like about it that with a turret gun with over 5 newish #64’s oodammo breaks upon firing so you can’t really get the full power of the TR8 and still use oodammo. One solution is some tape but that causes drag. I almost always use an oodammo sidearm. Oodammo is second best to finammo (and its slingshot variants).

Slingshot ammo is ammunition used in slingshots such as the SRV1, SRV2, and SRV3. It is considered to be the most powerful K’nex gun ammunition provided you have fins. I’ve never made an SR series gun due to laziness and only having a few hinges. Based on what I’ve read and heard, it can go over 500 feet! Pretty good! It is not good to use indoors but it’s fine for outdoors for sniping. Rate of fire of all the guns that use it is really low but the range is great.

Cannon ammo is the ammunition along with modified grenade versions that is used in K’nex cannons. I don’t really like this type much because the back red connector tends to break off if left loaded too long. This can be solved with glue, heat shrink, or tape. Another method of solving this problem is to leave the bands hooked on the part of the gun they go on while you’re getting the projectile in but only put them on the projectile when you want to shoot. Depending on the gun, cannon ammo can go around 60 to 120 feet. It’s good for destroying box forts and such. I use a small cannon as a grenade launcher/box for destroyer. Cannon ammo is ok for the uses previously listed but a cannonier will be outgunned by people with TR’s and such. If you insist on this play style, it’s best to carry the cannon on a sling in the half-loaded mode described early while using a TR or an Oodassault for close combat. Never use a cannon for CQC, you’ll be outgunned and they hurt a whole bunch. I recently used the handheld heavy cannon to demolish some box forts being used by kids on my street. They used nerf guns, I used K’nex. I just got sick of darts hitting my window, lol.

Fin ammo is the best ammunition for TR’s and NAR’s. I can confirm that well-made fin ammo shoots about 300 feet with no wind from a TR8 with 7 #64’s provided it’s shot from a 45° or so angle. It is great for sniping and just general use in a war. Even poorly made fin ammo can hit respectable distances. Even on somewhat windy days it can go 150 feet. Red rods work best with fins while yellow rods can work ok too, I mostly use the yellow rod variant in small turret pistols. The only downsides are it takes a while to make and there is a very small margin for error if you want 300 foot ranges. Kyle_M wasn’t lying when he made those claims about his TR-8, any problems you encounter are caused by human error (almost always the fins).

Step 4: Conclusion

Finammo is the best type of ammunition with oodammo being second best. Oodammo is less accurate than finammo but it is smaller and much faster to make.