Gravel filled walls.

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Rob Painless

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I originally posted this on another preparedness site..............

I built a small wall with 2x4 framing, 4' wide by about 2' tall, and sheathed it with 3/4" CDX (plywood) on both sides, leaving the top open so I could add/remove the fill. For this test, I used simple pea gravel (because that's what I had) and filled one of the cells, 14" wide, almost to the top of the opening.
I set the test wall up in the field next to my house, marked the area which I wanted to shoot and backed off to about 165' (55 yards) away.
I fired 3 shots from a bolt action rifle with 22" barrel using .223 55 gr FMJ ammunition and then 5 shots from a semi-auto rifle with 18" barrel using 3 rounds of .308 150 gr jacketed soft point (a hunting round) and then 2 rounds of .308 150 gr FMJ. All shots were in an apx. 1 foot square except for 1 shot of each caliber which I aimed high, just below the gravel fill line as a test for that area.
I am pleased to report that there were ZERO penetrations out the far side (exit side) of the wall. Wow. I really thought the .308 FMJ's would have needed at least a 2x6 frame to stop them from passing through.....but not so.
Next test was to fill one of the two remaining cells in the wall with sand/dirt and see what would happen with that. The results were not too great. Almost everything went all the way through. The only thing that got stopped was a couple of .223 soft point rounds. Better than nothing? Maybe. But I wouldn't want to count on it.

I'm having problems loading pictures, but will when the problems stop.
 
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What you brickwork 2 bricks are not satisfied ???
2-5-300x300.jpg

In a qualitative brick and cement wall which withstand not only 50BMG and even 23mm
 
Sandbags do work (so dirt), but typically, the guideline is to have two layers of it, (and each is already about twice as wide or more than your 4"). Other ideas I've seen though, are filling tire stacks with dirt, concrete block (of course, with rebar and poured concrete inside), etc. Those new modern ones (that can be filled with dirt) are awesome too, but suspect they'd be hard to get.

A brick and cement wall, would of course, be damn tough as well. We're doing out planters (i.e. pillbox sentry stations) with concrete block, rebar, and poured concrete). They'll be planters pre SHTF, but easy to convert after.
 
A brick and cement wall, would of course, be damn tough as well.

Indeed. I think it would too. But it would also probably be damned expensive & time consuming. But if done right, could be very aesthetically pleasing. Gravel is cheap by comparison and pretty easy to use. I also like the fact that it is hidden, which keeps others (bad guys) from being able to plan ahead for defeating or getting around it. The downside, of course, is that it takes a little effort to incorporate it into existing construction. But it is super easy to put it into new construction. Medium easy if doing a remodel to existing walls. Really good fire barrier, too, as well as reasonably good insulating properties.
Curious about how tall your planters are. Also curious if you have built a test model to shoot at & see how well it holds up. That would be good info to share. I have wondered about that kind of construction.
 
We plan on making them basically 4 blocks high. There will be 3 removable openings about the size of a standard brick (not block), for firing ports. In pre-SHTF planter mode, there will be bricks blocking there (with a screwed in ring to remove, then with the rings facing in for removal from that side). Post SHTF, we dig out the dirt and plants, and a cover will bolt into place (keeps rain off, incendiaries), for the sentry.

I haven't built them yet, as I have to budget for the blocks, rebar, and cement. Most likely, I'll only pour cement in the same columns as the rebar, with gravel in the rest.
 
I haven't built them yet, as I have to budget for the blocks, rebar, and cement. Most likely, I'll only pour cement in the same columns as the rebar, with gravel in the rest.

Cool! I like your ideas. Concerned about the blocks/cells that won't have cement in them. Cinder blocks tend to fall apart quickly under bullet strikes and could possibly dump any loose fill, leaving your fighting position less protected & vulnerable. Build a small sample wall & shoot it several times with different caliber weapons....then let us all know how it held up! Hmmmm....maybe I will, too. If I can find time to add another thing to my schedule. o_O
 
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Concerned about the blocks/cells that won't have cement in them. Cinder blocks tend to fall apart quickly under bullet strikes and could possibly dump any loose fill,

A valid concern. However, post SHTF, we will have sandbags as well. I was just planning on one thickness on the outside, to kind of help out the concrete. (we'd be using the dirt from the planters to fill them)
 
I originally posted this on another preparedness site..............

I built a small wall with 2x4 framing, 4' wide by about 2' tall, and sheathed it with 3/4" CDX (plywood) on both sides, leaving the top open so I could add/remove the fill. For this test, I used simple pea gravel (because that's what I had) and filled one of the cells, 14" wide, almost to the top of the opening.
I set the test wall up in the field next to my house, marked the area which I wanted to shoot and backed off to about 165' (55 yards) away.
I fired 3 shots from a bolt action rifle with 22" barrel using .223 55 gr FMJ ammunition and then 5 shots from a semi-auto rifle with 18" barrel using 3 rounds of .308 150 gr jacketed soft point (a hunting round) and then 2 rounds of .308 150 gr FMJ. All shots were in an apx. 1 foot square except for 1 shot of each caliber which I aimed high, just below the gravel fill line as a test for that area.
I am pleased to report that there were ZERO penetrations out the far side (exit side) of the wall. Wow. I really thought the .308 FMJ's would have needed at least a 2x6 frame to stop them from passing through.....but not so.
Next test was to fill one of the two remaining cells in the wall with sand/dirt and see what would happen with that. The results were not too great. Almost everything went all the way through. The only thing that got stopped was a couple of .223 soft point rounds. Better than nothing? Maybe. But I wouldn't want to count on it.

I'm having problems loading pictures, but will when the problems stop.
I'm really impressed with your results. I would have guessed gravel would be better, but would not have thought by much. I'd like to test a solid concrete filled block. It would stop a round, but might start to crumble after many shots. Thanks for your effort on both testing and posting the results.
 
well I am thinking 80# sacks of ready mix concrete, 30 bags will make a wall 10 ft long 2 ft high cost about $120.00,I have plans for a bunker and surrounding the Hatch with them I might even do a double row and go 30 inches high,when the wall is finished throw some dirt on it for camo and plant some grass on it
 
well I am thinking 80# sacks of ready mix concrete, 30 bags will make a wall 10 ft long 2 ft high cost about $120.00,I have plans for a bunker and surrounding the Hatch with them I might even do a double row and go 30 inches high,when the wall is finished throw some dirt on it for camo and plant some grass on it
As far as a good defense wall, just a mound of dirt is excellent. Good old dirt will stop just about any projectile. It absorbs the impact, dispersing the energy without hurting the mound. Later you could even dig the lead out and send it back to the attackers! Seriously, a three ft thick mound is cheap, effective and could be worked into a landscape theme, as you don't want something that screams 'hey, I've got a bunker full of supplies here'. Having a backhoe to move the dirt is kind of a must though.
 
As far as a good defense wall, just a mound of dirt is excellent. Good old dirt will stop just about any projectile. It absorbs the impact, dispersing the energy without hurting the mound. Later you could even dig the lead out and send it back to the attackers! Seriously, a three ft thick mound is cheap, effective and could be worked into a landscape theme, as you don't want something that screams 'hey, I've got a bunker full of supplies here'. Having a backhoe to move the dirt is kind of a must though.


I live 3.5 miles down a dirt road there are 4 ways in ,one has a old bridge over it,blow the bridge and block 2 of the other 3 with trees,even for anyone who knows the area there is not much reason to come back in here,trash up the area around the house give it that no one has been here for years look,I may never have anyone even look at the place
 
the gravel is effective because of the gaps between each piece and it redirects bullet path due to all of the angles the gravel has and better hardness compared to the dirt sand at the thickness you are using...no two bullets every do the same thing when they strike something....FMJ bullets will fall apart like soft points and sometimes stay intact....no guarantee...a small fast fmj bullet from a 5.56/223 rifle does all manner of things once it hits something versus a large 50 BMG fmj round that tends to push through using the high amount of energy....gaps in layers of protection( dirt, rock, wood ) will always have a better stopping chance than no gaps in material...until of course you wall is so thick it would stop any round, if you have room for that much thickness...
 
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