The key points to concrete:

Get the highest quality you can buy. Still very cheap for the amount you get. There is stuff with fiberglass and its quite good. Some of the cheaper stuff with gravel is garbage. Experiment until you find one that works.

Get the water content right. You want it to shape with no visible cracks on the surface but just to that point. It needs to be stoff enough to hold it's shape when  you put it in the egg crate.

You can add a little sand to the mix to make the over all ammo smooth on the surface. At the cost of some density and possibly some durability. It's your choice.

Lastly, find some way to compress it. Either with your hands or with a meatballer. Plastic Easter eggs can work but I doubt you will ever hit the minute per shot mark. Likely not even close. Meatballers or better yet your hands are much fast and even so you will struggle to break even at one minute per "good" ammo. It's right at that point though if you don't count prep and clean up.the more compression the less water you need and the stronger and denser the resulting shot.

After shaping is done and you have a good amount of ammo wait 30 minutes and spray the ammo with a fine mist of water thoroughly. Then close the egg crate lid or better yet put the whole crate in a rubber maid container with tight fitting life and spray the entire inside. It needs to stay very moist during curing for maximum strength. 3 days is useable, 2 weeks is ideal for curing.


High quality concrete ammo is the best pound for pound ammo I've ever use. Highly durable when made right, very cheap, as perfect as you can hope for in weight/shape/size. Even so make sure you have a backstop or you will be making thousands of shots over your slinging adventures. Speaking from experience here. The backstop is the unsung hero of the slinger.

Good luck!

I agree, water content. You mentioned in the first video its too wet at first. You're right. That was way too wet. But afterwards it looked drier when you were shaping it? Correct me if Im wrong here. Water content is actually super important for good concrete ammo.

What I usually do is get it really close to the correct water content, shape it roughly to the desired egg shape (by hand/meatballer) then lightly spritz it with the water bottle. The amount you can add to the water content with a water bottle is very even and controlled.

I "think" you're having issues because of the plastic eggs. Dry enough not to stick means not enough water. Its possible you can spray it with the water bottle but it seems like thats not adding an even enough water content throughout to make the optimum cure. That's my best guess. Any "gluing" is really sensitive to correct pressure vs "wetness". Also might not hurt to always wash the sand. Correctly done the strength is much, much higher than when things are just slightly off. Doesn't seem to be much room for error.

As for compressing you will feel the mix shift within itself as you compress it. A little too wet and its like compressing mud. i.e. impossible. A little too dry and you wont feel anything shifting either. It's all about the ratio of water. Might also have to do with the type of aggregate I was using personally, but I would be surprised if you couldnt compress those at least a little.

If everything is correctly made and compressed you can take the just made ammo and lightly knock it on the table (work surface) and it wont affect the ammo shape or break. It will almost feel set, Although if you tap it too hard you will see otherwise.

The best/strongest ammo I've made was with a meatballer. You can really put a lot of pressure on the ammo when making it. The steps are spray meatballer, dip in fine sand, shake off excess, put your mix it, squeeze like hell and take out.

I had one set that was particularly strong where for kicks I threw by hand point blank at the concrete road and it didnt break after three or four throws. These were hard throws too. Anyways, it will outdo clay by a long shot.

EDIT: I have never checked density but I would estimate it is within 10-20% of a good river stone. That's my wild guess, don't quote me on it.