Full Auto Bb Gun





Introduction: Full Auto Bb Gun

A full auto bb gun my dad made out of store bought hardware stuff nothing else. The question is: can you do it? Go ahead and give it a try!

Hint: There's more than meets the eye!




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    52 Discussions

    hey whats up i just thought id post the finished product it still shoots like crazy and hard too at 155 psi


    Interesting. Full auto's are easy though. I'd like to challenge you to develope a reliable semi auto that can fire as fast as you can pull the trigger. I've built several semi autos and there are much harder than an auto.

    What do you say?

    2 replies

    I realize they are harder! I don't have the tools to do this anymore, but i'll relay it to my dad who does!

    Great! I look forward to hearing your results.

    I'm part of the RC Warship Combat community and we build single shot bb guns that fire with Co2 for our boats.

    I'm guessing the metal pipes connecting in between the nozzle thingy a nod the piping is to balance the airflow.

    What causes the air to divide so some goes to push the BBs through the tubing and the rest down the barrel? Why doesn't the air go into the coil from both places where it tees to the barrel? What makes the air stream split through the coil and push BBs around and into the air stream to be forced out the barrel? Do the BBs enter the barrel at the tee close to the blow gun or at the tee closer to the barrel tip? Is a check valve used somewhere? If so Where?
    Great design! Need a close up picture of the fittings connecter together. Can't see enough detail from the video. Will you post one close up picture, would really help!


    If you look close you will see a pipe plug by the handle of the gun. That is where you load the bbs. you can see it if you stop at around 53 seconds its the piece in the wood, with the pipe plug removed. (the wood is to just hold it in place) you just drop the bbs down that.

    thanks i really want to build a full auto bb gun and cant decide between making one similar to this or one with a vortex block any recomendations?

    this design is much harder to build and tune to make work, if you are make it with Mr. clean's design. it is much easier. but the advantages to this design is the fire rate and power are consistent and adjustable, with a vortex block it varies too much to be consistent.

    Can you please tell me in what kind of shop can i find hydro-formed copper tubing?Or what is the general purpose of it?Because i couldn't find that part.And btw I accept your challenge :)

    2 replies

    Its just regular copper tubing to hydro form it just fill it with water and plug both ends with something that wont come off under pressure, then bend it around a piece of PVC pipe the diameter you want it to be. then drain the water out and presto! you do that so it doesn't kink when you try to bend it.

    I hope i can find it.btw it is the same diameter of a bb?Or is it larger like 7-8 mm?

    That tubing was a good idea with the quick connects. We had no quick disconnects at the store but my dad uses them at work and it would have saved a lot of time. The valve you put on was a really good idea. We used a restrictor and had to play with it to get it right. Congrats on the good thinking on the design! On the loader we used copper tubing and there are magnets on each tube that when the slide is pulled the magnets release the end tube first and hold the others in place (the whole slide is full of magnets) then you keep pulling and emptying each tube at a time. You could also use one long tube. The V block is made out of wood so you can shake the bbs into place. If the loader is half as good as your gun it would be the best we have seen. Good Job! On the barrel we used 1/4 inch brake line at any car part store. (if the plastic would ware out or kink. That brake line is flared at the ends for better airflow and bb entrance. Good luck and let me know!

    2 replies

    a little while after my last post i added one more valve between the loading end of the magazine tube and the quick connector to control the feed of the mag it seems to work great and that was also one problem i experienced too was that the air would take the path of lest resistance and the bbs wouldn't feed so i added that valve so i could control the flow and get more air to enter the mag but theres no need to even close it at all it added the perfect amount of resistance. but if u have any more brake line left try making the barrel longer u wont believe what a difference it makes in the bbs power but it may slow the rate of fire right now my barrel is around 4 feet and even at 40 psi it embeds bbs into a 2x4. when i finish it ill post pics :)

    Can you make a tutorial on how to make a gun like that? I REALLY want to make one :D And the gun that you made looks pretty cool :D

    Its VERY simple use a portable tire refill tank that holds 175psi and fits in a backpack