I've got a bank behind the shop.  I'm thinking of digging out a section and filling it with sand for a broadhead backstop. For those of you who use sand pits, how deep do your broadheads penetrate into the sand?

gday, i practise into a styrofoam box filled with moist sand. won't go in that far as to harm your feathers. i've got a sand mound as a back stop behind the box. not that i miss the box. (yeah right) LOL. bonus, you can draw your target on the box. and you shoot at a vertical target, not a slope. this gives you the proper indication as to the windage and elevation.

I shoot in dirt all the time; I have the only hill of it in Idaho.
   

He and his buddy had decided to build a fort behind the target !    

So; I checked each time I shot... a lesson learned!

In dirt like I shoot into now; I get about foot of penetration. I think the syrofoam box idea is a good one.

I think I will put a bag of potting soil with sand mix in my wifes flower bed and shoot.When it starts tearing pour the contents in bed and move a little further and get another bag recycle the targets.Kip

I maintain over 40 sandpits btween my archery club and home. Penetration can vary a lot depending on conditions. Wet, dry, coarse, fine, etc. With a fast high energy compound it is not unusual to have to dig in 8 - 12 in. to find your nock under dry conditions. For trad gear penetration is usually no more than 1/2 the arrow length.