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Posted: 1/12/2013 11:35:56 AM EDT
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A local shop that does waterjet cutting of various materials gave me a few samples of some cut-off scraps from a job they are always running. They're clear Lexan, about 5.5 inches in diameter and 2 inches thick. Not knowing what to do with them, I figured, let's shoot 'em and see how they can take a bullet. This one was shot at a range of about 50 feet using my M4gery, shooting Sierra 53 gr. Match Kings with a load that clocks out at 3200 FPS out of a 20" barrel. This rifle having a 16" barrel, the MV would be a bit lower but as I don't have a chrono, I can't say by how much. I shot a couple of these but this is the only one that gave me the sort of results I wanted. The others were not so well centered and/or got blown to bits by a follow-up shot. I wanted to put a .45 into one as well. Maybe in the next batch. The results speak for themselves. 2 inches of Lexan (of this particular type, which I don't know at the moment but I can find out) is quite adequate to keep a 53 gr. .223 bullet from penetrating. The deepest point of the penetration is about 1.2 inches out of 2 inches of material. The piece continued to experience growing cracks and some pushing out of the impacted area for several hours. Understandable since it's been massively stressed and internally deformed. I can get my hands on literally hundreds of these Lexan circles. If I had way too much time on my hands I could have them all waterjet cut to hexagonal shapes and then tile them together and make a cheap but reasonably effective bullet-resistant window. I don't have anything heavier than .223 but my guess is that .308 would simply destroy one of these things.    I thought you might find this to be moderately interesting. I'm going to turn the piece into an ornament. It'll be lit from the edge with a bright white LED. CJ |
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I'll be more than happy to get the exact specs of this particular type of Lexan and then shoot samples with a variety of ammunition for your education and amusement. I only need one round each. Next up: My 77 grain Match Kings out of my SPR. I expect substantially more damage. I'm sure I can score a round each of any type of ammo you want to see tried out. CJ |
. Just kidding
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If you want some, just PM me. I can probably stuff them into a flat rate priority mail box for $11.35 (medium box) or $15.45 for a large box. Either way I'll fill the box up. That's what postage costs. I'm not asking for any money for the Lexan discs. Just cover the shipping. |
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Lexgard is a bullet resistant multi-layer polycarbonate (lexan) that is used in bank teller windows and convenience stores. Type mp750 is 3/4 inch thick and is rated for level 1 (9mm) protection, type mp1000 is 1 inch thick providing level 2 (.357 mag), and type mp1250 is 1.25 inches thick providing level 3 (.44 mag) hand gun protection. A clear one square foot (12x12 in.) of the mp750 runs around $90.
Usually anything thicker is rated for military use or private security use and they don't provide much info on the stats on these materials. wolfganggross |
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The layering is the key. I was a glass installer for 10 yrs. Did a few jobs at banks with true bullet resistant glass and plastics as well as non translucent panels. They are all layered materials. The layers "catch" the bullet much better than a solid peice of the same material. They use a layering material that is similar to that used in car windshields. If you've ever had a rock hit your WS at high speed and just crack it a little or maybe do nothing you know about the layer effect. Car windshields are less than 1/4" thick overall and the glass is about 3/32" each peice. If you threw a rock at a single layer of that glass it would easily break like a house window pane. Automotive glass is also partially or totally tempered "heat treated" if you will just like metals.
If you really want to get some reistant panels try layers. Id not recomend the hex or oct joining as the seams would be much weaker. If a shot landed rite on the seam it would penetrate much further than youd expect. That said... Its fun to shoot! I bet a .308 wouldnt fare much better. From what I understand velocity is more critical than energy. .223 bullets are hard to stop. I bet a non tumbleing bullet would be very hard to stop. Id love to see a .45 shot in the same material. I would predict it will barely penetrate and the bullet would be mostly undamaged. Id really like to see it shot with a .223 wssm... Prolly drill a hole rite through. |
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These pieces are the leftovers from a job. I can have as many as I want but only what's there. They start out as foot square pieces. If someone were to want to use these as a protective shield, cutting hexes on them would be the most efficient way to tile them together without gaps. Of course you'd rather have solid material but I don't have bigger pieces and can't get them without spending a lot of money. I did pop off a couple of .45s at them. The piece had already been shattered when I shot it with the .45 but the point where the bullet impacted was almost pristine. No cracks penetrating more than a sixteenth of an inch. In essence, it IS bulletproof to .45s unless the bullet hits an already compromised area. I want to repeat the experiment with one slab dedicated to one designated bullet each. Mark them for what they'll get hit with. CJ |
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I just picked up a good load of these discs today and will be shipping some out tomorrow. Those of you who wanted some will be getting them shortly. I popped off a few rounds at a couple this evening. One of them withstood ELEVEN hits from full house PMC .45 ammo, 230 gr. FMJ, before finally breaking in half. Eleven hits from full house ball ammo.  Most of the hits barely marked the surface of the material. NONE penetrated more than 1/8 inch. ALL the hits that struck at an angle (estimated 45 degrees or so) simply splashed/bounced off and barely even made a rub mark on the polished surface. ONE hit on a second disc, taken at an angle, did something interesting: While the bullet bounced off and splashed, the back of the disc along the direct line of the shot blew out a chunk about two inches long, an inch wide, and half an inch thick. There was no other damage between this point and the point of bullet impact. Another shooter popped off a few 9mm rounds at a disc at my invitation. They barely left a mark. I'd say this Lexan (Lexan G, to be specific) is quite adequate as improvised ballistic protection for most any pistol caliber. I doubt ANY pistol caliber is going to easily defeat 2 inches of Lexan G. Well...maybe the S&W 500, but my guess is that even that won't be assured of breaking a piece with EVERY shot. CJ |
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Those of you who have paid shipping will be getting their lexan discs shortly. They all shipped out today. I can get more but I won't be able to ship out until next Saturday as it's the only day I can get to the post office while it's open. Please note, if you choose to pay shippging via paypal, send the money as a gift so that I receive the actual cost of flat rate priority mail shipping and no fees come out of it. I'm only asking that you pay shipping, but that you pay ALL of the shipping. Not shipping -3%. I still have to put a little time and effort into getting them and shipping them out to you. CJ |
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