Sand backstop and penetration boxes

[getitdone1]

Here's pictures of my sand backstop and penetration boxes. The long penetration box could be used with wood and metal rather than sand.
The holes made by the 45-70 leak sand much more than the other smaller calibers. 22's no problem at all unless you get two or more hole touching. May buy some rubber tomorrow and screw and glue it on to the front of the backstop box. Have to get a good, strong seal. This "Play Sand" leaks through a tiny crack and yet hardly at all through a 22 cal. hole.

Sand is very different from animal tissue and yet it is interesting to see the bullets performing--relatively speaking--similar to how they perform with the water jugs. I'm guessing wood would do the same and may find-out.

First here is the sand backstop box. It's 8" of sand may not stop your bullets and if several bullets are lodged in one area you may also penetrate the box. I know my 375 H&H with Hornady 300 gr solids will penetrate this box. This box is for soft point bullets. FMJ or solid bullets may and sometimes will penetrate this box. TEST SAFELY TO KNOW FOR SURE and go with plenty of sand depth. 4" or more of sand beyond your deepest penetrating bullet would be a good idea. A thick metal plate leaning against the back of this box would be a good extra safety measure. IF NOT IN OPEN RURAL AREA FORGET THIS IDEA. You can miss the box and I have when shooting fast. Inexperienced shooters may miss it and depends on the distance you're shooting.



Here's the sand box built to test for bullet penetration in sand. 22 LR only made it into the first compartment. 308 Winchester soft point made it into the second compartment. 375 H&H with Hornady 300 gr solid made it to the back of the 5th compartment. Each compartment holds 2 1/2" thickness of sand.



Remember: This is "Play Sand" I bought at Lowes. It may be finer and thus harder to penetrate than regular sand. Another type of sand may require more depth of sand.

You'll notice lots of tape covering bullet holes near top of backstop box. I shot high so I wouldn't have to dig so deep to find bullet and bullet penetration depth. Shooting lower in the box would surely make for a little harder penetration since the sand would be packed more tightly there. Water jugs are a lot nicer in this regard. Had to clean all the sand off of my hands before handling guns.

Don

[Whit Spurzon]

Good stuff. Thanks for posting.

[getitdone1]

I'll soon take pictures of the bullets along with commentary. Many, about half, totally fragmented. The sand is especially tough on bullets traveling at high velocity--even tough and FMJ bullets. A lot of fragments and rough, jagged bullets come out of that sand.

I'll also include some bullets that went through water jugs. You'll see some beautiful mushrooms here. The Sierra 300 gr HP 45-70 loaded hot flattened-out like a washer. Would be wicked for self-defense. It also made a head of cabbage disappear into a cloud of mist. Well...there were some pieces left but most turned to mist.

Don

[rantingredneck]

Nice work.

My father in law and I built something similar a few years back. He was working at a rock quarry at the time and had ready access to rock dust. It's a bit coarser than sand, but not quite what you'd call gravel. built a box that looked similar to your first pic. 2x10 framing with plywood front and backing. We filled the chambers created with rock dust.

We never had a round exit the backside and we were shooting it on the narrowest axis. In other words 10" of rock dust stopped everything we threw at it, including 250gr JHP's out of our muzzleloaders, 150 gr. .30-06 corelokt JSPs, and anything we could fire from a .45ACP, .357 mag, and even my .454 Casull (240gr. Hornady XTP's at ~2000fps).

As you experienced, most rounds grenaded within the first few inches of dust.

The other benefit to the rock dust is that it's so coarse and irregularly grained that it doesn't quite flow like sand does and didn't pour out the bullet holes until we got the wood pretty well chewed up from concentrated hits.

[getitdone1]

rantingredneck,

Interesting about the rock dust. How consistent in size is it? This would be a factor for consistent results. Your 2x10 framing is better than my 2x4--more solid/stronger. The main point is if it will stop all the bullets, doesn't matter if it's real consistent. Just wondering though if you'd get larger pieces in one spot if bullet would go on through. So safety does come into play here. I have a similar concern if you'd get many bullets in one area and then possibly penetrate the box. Significant sand leakage is no fun. Today I bought a four foot piece of rubber matting which is about 5/16" thick. Squeeze it at the edge, release and it comes right back to full thickness. I'm going to glue and staple it to the front piece of plywood. Be running glue beads pretty close so as not to have a "sand buldge" in the rubber. Glue, made by Loctite, is supposed to be stronger than Liquid Nails and compatible with rubber and plywood.

Don

Nice work.

My father in law and I built something similar a few years back. He was working at a rock quarry at the time and had ready access to rock dust. It's a bit coarser than sand, but not quite what you'd call gravel. built a box that looked similar to your first pic. 2x10 framing with plywood front and backing. We filled the chambers created with rock dust.

We never had a round exit the backside and we were shooting it on the narrowest axis. In other words 10" of rock dust stopped everything we threw at it, including 250gr JHP's out of our muzzleloaders, 150 gr. .30-06 corelokt JSPs, and anything we could fire from a .45ACP, .357 mag, and even my .454 Casull (240gr. Hornady XTP's at ~2000fps).

As you experienced, most rounds grenaded within the first few inches of dust.

The other benefit to the rock dust is that it's so coarse and irregularly grained that it doesn't quite flow like sand does and didn't pour out the bullet holes until we got the wood pretty well chewed up from concentrated hits.

[getitdone1]

If I did this sandbox/bullet backstop project again I'd go with STEEL but maybe use a plywood and rubber front that would slide in and out for easy replacement. This would eliminate the "will it stay together over time" problem and also make it more weatherproof. I'd put a couple of pipe drains at the bottom of both sides for ease of emptying and then I'd make it twice as big to eliminate any doubt about possible penetration. The 45-70, 405 gr factory load just about went through this 8" box--and it's a soft, flat point. (Actually 8" of sand plus 1/2" plywood, front and back.) So you can see, you have to really be careful and know for sure. A way to be sure would be to tilt box and if you fully penetrate the bullet then goes into the ground. I think you need at least 2" of sand in front of the deepest penetrating bullet.

I like to slap the box with my hands after I fill it to settle/compact the sand. Then I usually add a little more. Shooting near the top of the box would probably make for easier penetration than lower where sand is more firmly compacted.

A more complicated, expensive and better backstop would be one made of thick, special tough steel angled so bullets would deflect and go into the ground. Put it on wheels for mobility. Thought about building it but don't think I ever will.

The very best backstop is a big, tall and wide mound of dirt--like at many of the shooting ranges. I know of a shooting range that has mounds of dirt I don't think are nearly as tall as they should be. Mobility is nice and of course you don't have it with this.

I've mentioned that I live in an open rural area and expect some would question why I even need a bullet backstop. For occasional varmint shooting with fast fragile bullets, I don't, (I'm still conscious of direction of shot) but for lots of shooting in one direction I want to know for sure where all types of bullets will stop. We used to hunt squirrels with 22 rifles. Now, I wouldn't do that in this area although I'm sure some still do.

Have a neighbor who lives about a mile away and he said they had a bullet come into their house. Happened several years ago--and, I'm not the shooter! So even here in the country, where in two directions houses are at least one mile away--I have to be careful. I never shoot in the direction of these few houses, even when shooting into the ground testing a reload for pressure signs.

Safety really does come first.

Don

[rantingredneck]

rantingredneck,

Interesting about the rock dust. How consistent in size is it? This would be a factor for consistent results. Your 2x10 framing is better than my 2x4--more solid/stronger. The main point is if it will stop all the bullets, doesn't matter if it's real consistent. Just wondering though if you'd get larger pieces in one spot if bullet would go on through. So safety does come into play here. I have a similar concern if you'd get many bullets in one area and then possibly penetrate the box. Significant sand leakage is no fun. Today I bought a four foot piece of rubber matting which is about 5/16" thick. Squeeze it at the edge, release and it comes right back to full thickness. I'm going to glue and staple it to the front piece of plywood. Be running glue beads pretty close so as not to have a "sand buldge" in the rubber. Glue, made by Loctite, is supposed to be stronger than Liquid Nails and compatible with rubber and plywood.

Don

Don,

It's consistent "enough" if that means anything. It's not as uniform as sand but there's definitely a high and low end range to the sizes. Once you pour it into the box and it settles in place it all sort of locks together into a pretty dense matrix. I wish I had photos of it, but our box rotted down within a few years and we didn't re-build it. We don't shoot on his property much anymore as I have a membership at the local gun club. He's also retired from the quarry now.

I was going to suggest a rubber front to help keep the leakage down to a minimum. Where I work we use an extruded foam insulation to build custom fittings and that material would seem a likely candidate for something like this.

[rogn]

Weve been using 30 gallon chemical barrels as backstops filling them with the local subsoil(sand with a touch of clay. The barrels are staggered so there is no open space. 3 in front and 2 in back. My thought is that the polyethelene that these barrels are made of is very self healing for 100s of shots and if the calibers are small and pointy , they leak hardly at all. Flat point 9s, 10s and 45s do wear them out pretty quickly, too much like a ole punch. Bullets into wood, is a different matter, Fragile HV soft points dont go far in hardwood, while Things like Nsler partitions and Barnes TSXs get from 3-to 7 inches. Hevier for caliber and higher vel at the same time get the most penetration. Bullets also quickly chew a portal thru wood, whereas the sand if its dry will just settle right back in. FMJ are their own stories, in the sand barrels they dont do much differntly than heavy soft points. 223 and 308 FMJ in wood are unpredictable. The 223s will usually quit in about 6-10 inches and the 308 150 gr a bit more, bot some of them will walk thru more than a foot, and go places unknown. Back when I was a teen, I popped a big 3' hickory with a 7X57 milsurp 173 gr, and found a four foot trench in the dirt on the other side of the tree. The neighbors cows all escaped unhurt. Mushrooms in moist fine sand and hardwood, with sturdybullets look alot what youd find in heavier game. it is interesting to find some of these terminal effects.