I know I cant be the first with this idea, shattering targets...

[brush hunter]

we save milk jugs and fill them with water and freeze them, a little food coloring gives them color. We take them up to shoot in a big cooler, than cut the plastic off before shooting. You can also just use water in the jug but glue the top on, soda bottles work too.

[lokidog]

On the concrete topic, use a mortar mix as there would be no rock in it, it will eventually disintegrate, might be a few years but eventually it will.  As far as forms, get a couple bags of sand, dampen it, smooth it and then make imprints of whatever you want your target to look like.

[turkeyfeather]

If your looking for a biodegradable, environmentally safe target concrete of any sort is not the answer. Not to mention an uptight ranger or gamie will likely cite you for littering. 

[madcow41]

So I thought of something the other day that  I figured plenty of people have thought of before. For shattering targets like clays that you just want to set up and shoot. Less than $10 and you can easily make a ton and custom color and size. Buy a $3 or so bag of concrete mix, cheap can of spray paint and find as many things to use as forms as you want. Small as a bottle cap or big as a 5 gal bucket. Just mix the concrete, make a layer in it 1/2 - 1 inch thick, let dry, paint, set up and shoot. Does anyone see problems with this? All my buddies thought it was an amazing idea for the money, only wish we could find a way to make them fly well like clays. I imagine you could make a ton of them out of one bag of mix. Esp if you are making like 3 inch diameter targets. I know they may be brittle and could break in transport or taking out of the mold. I also thought of just doing the same thing with natural clay or even mud. I just think the mud would crack way too easily before you get a chance to shoot it. But it would be more nature friendly. I am not... (for the lack of a more politically correct term) a hardcore treehugger but I also hate seeing piles of shot up garbage and such just cause someone thinks it will look cool to shoot. Are most concrete mixes pretty natural? I also would like to set up realistic size targets compared to the vitals of a deer and of elk and put them in realistic shooting locations for practice for me and my stepson. What diameter would you think is best for these? 8-10 inches for deer and 15 inches or so for elk sound about right?

Whos gonna clean all this up once your done shooting? or are you to say it will look like rocks and this be ok? Now if it where biodegradeable that would be cool