Suitable backstop medium for big calibers

[kalipsocs]

Well now we got the .50 BMG, we have to build a range! My dad and I came up with building an outer frame out of railroad ties (sp?) maybe 10-12 feet high. My only question is will dirt be enough to stop those 600-700 grain FMJ bullets? I know depth is a factor, just don't know how much is enough. I assume this will become the default range for all our weapons, but it needs to withstand the "ultimate" test. So what do you think is the best medium to stop bullets with that kind of energy without being horribly expensive? Dirt? Sand? Still just brain storming at this stage. One thing is for sure there is plenty of dirt out there!!

[phddan]

Dirt is fine. No RR ties needed.
10' high is good.
One thing to watch out for is as the backstop is used, it will develop "hot spots". Areas right behind the targets that load up with lead. Every now and then, depending on usage, you need to break up the hot spots.

Dan

[Excaliber]

Dirt is fine. No RR ties needed.
10' high is good.
One thing to watch out for is as the backstop is used, it will develop "hot spots". Areas right behind the targets that load up with lead. Every now and then, depending on usage, you need to break up the hot spots.

Dan

The dirt needs to also be piled pretty steep on the side you'll be shooting into and the face needs to be kept fairly soft to make sure the rounds burrow in. I've seen ricochets off shallow angle dirt banks, and ones with hardened dirt on the face. Some Texas clay can act like cement when it's dry enough. You don't want that to happen with a .50 BMG round, or anything else that can travel far enough to be a hazard.

It's also a good idea to put a few layers of railroad ties in front of the berm at the bottom. It helps hold back the dirt from washing out and creating a more shallowly angled backstop over time, and tends to catch any rounds that hit short of the berm and might otherwise hit the berm at a glancing angle and skip over it.

[kalipsocs]

Dirt is fine. No RR ties needed.
10' high is good.
One thing to watch out for is as the backstop is used, it will develop "hot spots". Areas right behind the targets that load up with lead. Every now and then, depending on usage, you need to break up the hot spots.

Dan

Care to elaborate more on hot spots? What happens if they build? How do you break it up? etc.

[phddan]

Hot spots are where the bullets build up behind the targets in the dirt.
When they build up enough, it can and will be solid enough to bounce the lead right back at ya.
Every few months I'll take the front end loader on my tractor and rework the berm face to break up the hot spots.

Dan

[KaiserB]

Hot spots are where the bullets build up behind the targets in the dirt.
When they build up enough, it can and will be solid enough to bounce the lead right back at ya.
Every few months I'll take the front end loader on my tractor and rework the berm face to break up the hot spots.

Dan

You may end up like this poor guy:

http://www.youtube.com/watch?v=vhysoS2D ... re=related