I'm finally back here

Hello Gwynedd,

Believe it or not, I kind of had that same thought right after I sent that last message. We KNOW the high velocity stuff can defeat a substantial amount of armour. Armour for the military doesn't often face a commercial magnum round though. I figured that if you were working with stuff for a tank or armoured car, there doesn't need to be a lot of technology behind it. Just about any reasonable weight of steel will defeat just about anything hand held short of a 14.5 mm Russian or a .50 Browning.

The alternative that I was guessing was add-on armour for a Humvee or Helicopter. I was figuring Humvee because the armour for a helicopter should be an integral / structural component for best efficiency when weight is a factor.

Just as a matter of note, as I see it, the 7.62 x 39 isn't a particularly great threat because from personal observation, they don't penetrate worth anything. I used to collect lead from the berms behind one of our club's ranges after closing. What I found was that I collected LOTS of 7.62 x 39 bullets because unlike most jacketed rifle bullets, they didn't dig themselves very deep into the dirt.

What is really cool for those of you who haven't done this is that after a good rain, you find bullets sitting on top of a little column of dirt because the rain washes away all the dirt that wasn't shielded by a bullet. This doesn't seem to work with anything below about .30 caliber though.

Besides the 7.62 x 39 and 7.62 x 54R, do you also happen to have a 5.45 mm gun? I personally have never owned or fired one of those.

BTW, I believe the Nachthexen were actually night bomber rather than fighter pilots. I can't imagine trying to intercept anything in a Po-2.

Best regards,
- Ivan.
 
Po-2 history lesson

Ivan said:
I can't imagine trying to intercept anything in a Po-2.
Click to expand...

Just quickly seeing this and not having time to look at any other posts so excuse me if this is off topic. In researching the Eastern Front for the 67th, I found out that the Po-2 was used for nuisence attacks at night. The pilot would cut the engine, glide in silently, drop the bomb(s), gun the engines, and get the h:censored:ll out of there. It never acheived much damage, but the point was more to disrupt the sleep of soldiers. The Germans had to scramble into the air after such an attack.:isadizzy: So essentially, the russians were bombing all the time when they had the resources. Mild attacks in the morning, Worse ones in the afternoon, the worst in the evening, then Po-2 attacks at night.:isadizzy:
 
This reminds me of a recent discussion I had about "bulletproof" vests... Someone referring to Flak Jackets as such... Pretty sure they are "bullet resistant"

Having done a fair share of "experimental" shooting at things:
The .50 S&W is a beast, and an absolute blast to fire. But as far as power, it is still lacking to rifles.
30-30's are very efficient at finely distributing cantaloupes.
A .300 will very nearly penetrate a very mild steel plate of ~1".

In the IDE building on campus, there is a 2" thick or so chunk of aluminum that was shot with a plastic BB, albeit at an extremely high velocity. The impact left a bowl shaped crater, complete with a "splash" appearance around the rim, that very nearly penetrated the slab. I used to have a picture on my phone.

I'd say, that there is almost nothing that you can't penetrate, given the right projectile, right power, and enough ammunition. :banghead:
 
Hello P&W,

I also have done a fair amount of silhouette shooting with a .300 Winchester Magnum but haven't had the same kinds of results. Then again, we were shooting the 1/2 inch steel targets from 200 meters.

- Ivan.
 
Ivan said:
Hello P&W,

I also have done a fair amount of silhouette shooting with a .300 Winchester Magnum. I'm not quite sure what version of .300 Magnum you are using, but a 1/2 inch thick sheep silhouette was pretty safe from penetration by the match 168 grain HPBTs we were using. It was suspended on ropes and being shot from 200 Meters out, but I don't believe we could blast through it even up close. Now perhaps with AP ammunition, we could have done better? Perhaps the sheep was hardened steel?

- Ivan.
Click to expand...

I would venture to guess that your sheep target silhouettes are a reasonably high carbon steel, and is probably quenched and tempered.

The piece of mild steel in question, I really believe was not only a weak alloy, but was also I believe annealed (as in, when it was cut out, it was heated to a temperature > 740*C, returning it to Austenite, and allowed to cool in air. It was a 4"x4"x1" piece, cut out on all 4 sides with an oxyacetylene torch.)

The piece was also pinned down, and backed by a piece of wood, IIRC... Shot from 20-50 feet. I am not sure what was used other than a .300 Magnum, I wasn't there when they shot it. I just saw the effects. They also shot another piece a few times with a .270, but with less dramatic results.
 
Let me answer both Pratt & Whitney and Ivan here because we're all on the same theme.
First, you are correct that nothing is truly bulletproof. Somebody can make something that can get through whatever armor you create. "Bullet resistant" is a lawyer term to avoid lawsuits from families whose husband, wife, son or daughter was shot while wearing armor that was not designed to stop the bullet that penetrated. Next, FLAK jackets are technically just intended for shrapnel and unless soft body armor is made to MIL SPEC for handguns and submachine guns, it is only for that use.
I have never fired a .50 S+W myself, but I have stopped the bullets from one in 1/5 of the layers of my military soft armor prototype at a range of 15 feet. I also have never fired the Russian 5.45, but I did let the FBI test some of my hard armor against AR-15's with 5.56 mm rounds. That round does not perform well at all in armor if you can destabilize it early, and that is really the design of the 5.56. It has a CG near the tail and tumbles in a target. The 7.62 x 39 is really not a high powered rifle bullet because it only has a muzzle velocity between 2200 - 2400 fps. The .30-30 has similar characteristics. They can actually be more devastating to some ceramic armors than bullets with speeds in the 2700 - 3200 fps ranges.
My task in the V-22 research is to find something to set behind the present carbon fiber composite skin. Carbon fiber is awful in ballistic applications because it is all Young's modulus and no yield at all. Ballistic resistance relies on both high energy to break and low breaking strain. Spider silk has been touted as a good potential ballistic material, but I think I was really the first person to point out to the Army that energy to break alone does not make a good fiber. Spiders kill by tiring our their prey in very resilient, high energy (work) to break, and mediocre modulus web before they poison them. The example I gave one of the women in that command was that if a vest stops a bullet without fiber breakage, but it stops a foot on the other side of the body from the entry direction, you have still killed the soldier. She quoted me in numerous meetings after that. I wish she had referenced me after the quote! :frown: Only a few fiber materials have the properties we can use and they include aramids (Kevlar etc), extended chain polyethylenes (Spectra etc), and poly{2,6-diimidazo[4,5-b4',5'-e]pyridinylene-1,4(2,5-dihydroxy)phenylene}. They call that last one M5, thank God. No fiber based material by itself can stop a rifle bullet more powerful than a .22 LR.
If there is any way to post a PowerPoint somewhere here on this board, I can do that for you guys. Otherwise, maybe a local university library can get you a copy of this book http://www.amazon.com/Military-Textiles-Woodhead-Publishing/dp/1420079603/ref=sr_1_1?ie=UTF8&s=books&qid=1226897632&sr=1-1 I wrote Chapter 2 or one of the early ones in there.
One question for you, P&W. You are only 21, but your avatar has a slide rule. Have you ever used one? It has been a long time, but I think I could pick it back up easily with all the practice we used to get.

Pratt&Whitney said:
This reminds me of a recent discussion I had about "bulletproof" vests... Someone referring to Flak Jackets as such... Pretty sure they are "bullet resistant"

Having done a fair share of "experimental" shooting at things:
The .50 S&W is a beast, and an absolute blast to fire. But as far as power, it is still lacking to rifles.
30-30's are very efficient at finely distributing cantaloupes.
A .300 will very nearly penetrate a very mild steel plate of ~1".

In the IDE building on campus, there is a 2" thick or so chunk of aluminum that was shot with a plastic BB, albeit at an extremely high velocity. The impact left a bowl shaped crater, complete with a "splash" appearance around the rim, that very nearly penetrated the slab. I used to have a picture on my phone.

I'd say, that there is almost nothing that you can't penetrate, given the right projectile, right power, and enough ammunition. :banghead:
Click to expand...
 
Gwynedd said:
The .30-30 has similar characteristics. They can actually be more devastating to some ceramic armors than bullets with speeds in the 2700 - 3200 fps ranges.

One question for you, P&W. You are only 21, but your avatar has a slide rule. Have you ever used one? It has been a long time, but I think I could pick it back up easily with all the practice we used to get.
Click to expand...

Thank you for taking so much effort to reply to Ivan and myself :applause: A lot of interesting info

I tend to drag my professors into discussions like this... :redf:

I tend to think of the 30-30 as a bludgeoning round, something almost more akin to a shotgun slug, in that it has a rounded/flat tip, and almost all the rounds I have encountered are lead nosed and are designed to expand quickly. So when the hit something that can give them enough resistance to bloom into a mushroom, they can deliver a nice chunk of energy to them. Not great for penetrating through a fiber-based like a ballistic tip might, but I could see why it might be devastating to a ceramic plate if it struck perpendicularly. From what I remember the CoM would be near the center or slightly rearward.

I am 21, and that picture is actually of Joe Miner, our mascot. Formerly the University of Missouri-Rolla, now Missouri University of Science and Technology :isadizzy: Anyway, I have yet to learn to use a slide rule (I'd like to, oddly enough). I've held one :d I'm in the process of chasing a degree in Mechanical Engineering.:running:
 
Hi P&W,

You quoted my original post. I went back to edit when it started sounding too much like an off topic argument. 200 Meters out DOES pull a lot of velocity off a .30 caliber bullet. It makes it behave more like a .308 Winchester up close.

Seems like we are all posting at the same time. Gwynedd, I just saw your post when I began mine. I was wondering a bit how a specialist in fiber technology would get involved with armour but it all makes sense. I would love to discuss the topic offline, but realise that I probably have nothing to contribute so it would be more like attending a lecture.

Great use of logic in your description of elastic armour to your client. Folks sometimes get caught up in the details without remembering WHY they were in the game to begin with.

I play a lot with small arms, but my direction is more toward getting the best possible accuracy with no consideration of terminal effect. Velocity is useful to me only to get the best trajectory and range and hopefully consistency. I tend to load ammunition toward the middle of the velocity range because that is generally where the best accuracy is and also because it should produce pretty much the expected results with a particular cartridge.

As you can see, I am reasonably serious firearms enthusiast and a mention of the subject will almost certainly get some kind of response from me.

In this case, the only useful information I can point out is that your potential threats may include a few more cartridges: 8 mm Mauser, and 5.56 mm rounds with a 62 grain steel core bullet (SS109?). I believe the 8 mm (or 7.92 x 57) was used extensively in Yugoslavia not too long ago. The 5.45 even with a steel core had fairly poor AP performance IIRC.

Good Evening.
- Ivan.
 
Ivan: I used to be somewhat of a gun slinger myself. It's been a while since I have been out to the gun range to make some noise.

I used to reload a lot of 12 gauge. Here's one trick I did a couple of times. I made solid plastic slugs from PVC tubing loaded in 3" hulls. Being such a light projectile, I must have been getting some crazy velocity at close range. A 2X4 at 60 feet and it went clean through it. Or a milk jug full of water, grab an umbrella, 'cause it exploded.

Why? Why not. It was kinda fun.
 
I think we are talking body armor?

~S~ All,

Rubber, would be a good way to slow or stop a round, but it would take so much no one would or could use it. Even with the steel breast plated Kevlar, most people stop wearing them after a while. They shift, they rub, they make you sweat like a pig. Bad guys shoot for the head. You could die from a scratch. It all seams like a great waist of time an money. You make a better vest, they make a better bullet. Tanks are not really bullet proof.

Work on robots and have the soldiers sit in front of computers in air-conditioned bunkers. Or better yet, bring out the neutron bomb and kill them all.

War, I know and there has to be a better way. If humans were honorable people and we had a dispute, we could each sent one champion to fight to the death. Not tens and hundreds of thousands of our finest. H:censored:, we elected our politicians to server us. Make them serve half their term in a war zone. Make them serve there whole term there and let some honest person represent up in Washington.

Oh well, time to return to my rubber room where I am safe as long as I where my aluminum foil hat.

j:isadizzy:
 
I'll try to answer two at once here.
That was a frangible, Skyferret. The state of the art now uses either brass and nylon composite that disintegrates shortly after impact, or a clay/polymer composite that is the most God awful hollow point you can imagine. It more or less explodes in the target. The one you made would be effective at close range, but if it did not kill the target, the ER would never find all the fragments because they don't show up on X-ray or echo in MRI.
Ivan, if I can post a PowerPoint here in some way, I will be glad to, but I don't know how. Is that possible? Also, I would be glad to talk off line. My public e-mail is gwen_thomas2000@yahoo.com
And I agree that other threats are important, but public universities don't buy guns for professors. I have to get my own. Most people are very stunned when they learn that a church lady professor in town owns over 20 firearms and ammunition, so I try to avoid the topic. The last 8mm Mauser I saw here was about $350, but it was in a shop frequented by KKK and drug dealer types and they hang pictures of Hitler in there. I'd rather not go in there without Obi-wan Kenobi. There is a new Academy Sports here in town near the Sam's Club and they have ads in the Sunday paper that look like price ranges I could afford about once a year. I guess I should get a 5.56, but the new 0101.06 NIJ armor standards call for a .357 Sig, and I don't have one of those. I need to find out if my 7.62 x 25 CZ52 can fill that role before I buy anything else.
And before you ask - I do keep them locked up and ammunition separate. ...Mostly.

Skyferret said:
Ivan: I used to be somewhat of a gun slinger myself. It's been a while since I have been out to the gun range to make some noise.

I used to reload a lot of 12 gauge. Here's one trick I did a couple of times. I made solid plastic slugs from PVC tubing loaded in 3" hulls. Being such a light projectile, I must have been getting some crazy velocity at close range. A 2X4 at 60 feet and it went clean through it. Or a milk jug full of water, grab an umbrella, 'cause it exploded.

Why? Why not. It was kinda fun.
Click to expand...

Ivan said:
Gwynedd, I just saw your post when I began mine. I was wondering a bit how a specialist in fiber technology would get involved with armour but it all makes sense. I would love to discuss the topic offline, but realise that I probably have nothing to contribute so it would be more like attending a lecture.

In this case, the only useful information I can point out is that your potential threats may include a few more cartridges: 8 mm Mauser, and 5.56 mm rounds with a 62 grain steel core bullet (SS109?). I believe the 8 mm (or 7.92 x 57) was used extensively in Yugoslavia not too long ago. The 5.45 even with a steel core had fairly poor AP performance IIRC.

Good Evening.
- Ivan.
Click to expand...
 
Empty Guns

~S~ G,

Empty guns are good when uses as paper weights. I have on automatic that has no round in the chamber, because of a known safety issue, with this brand name. Other then that, they are all loaded to the max.

Sorry to hear about the KKK. I am not sure which verity you have there, they are all different or should I say just confused about what is important. They busted a group of the white supremes kind near here a week or so ago, in Bogalusa, LA. The local KKK disowned them. The local KKK held a public rally last month at the Pearl River County Courthouse. I guess it was a membership drive. Most people went on about their own business, like they were not there.

As I recall, C.S.A General Nathan Bedford Forrest was the first Grand Wizard of the KKK. At that time they were anti-black and anti-Carpet-Baggers. Throughout there history they have been anti-everything. Irish, German, Italian, Japanese, Jewish, Commies, yadi yadi yadi. In other words, it is not just a black thing. Bigot de jour. The way I hear it the worst KKK bunch is in Missouri, but you would have to check with P&W, if he knows.

Forget the bigotry and get the Mauser. Academy is to high, check out the pawn shops and gun shows. Wal-Mart has some good prices on long guns. If you really want a good deal, get a FFL and buy wholesale.

j:isadizzy:
 
Ballistics

Reading this post with great interest. Over the last year i have been providing some firepower for a friend of mine who is developing better bulletproof glass. He used to be an ATO (I don't know the US translation but in English he was a bomb disposal officer). Retired, burnt out about 8 years ago and taken over the family chemical company. He was looking at using nano particles in plastics to improve the energy asorbtion between the sheets of glass for car windscreens. The glass does a good job of destabilising the bullet and the plastic polymer then absorbs more energy. Several layers of plastic and then some sheeting at the back to hold it all together. To pass the tests he had to put 5.56 and 7.62 nato rounds into the area without any fragments getting through and without losing too much visibility. I provided the 7.62 and a friendly Police Firearms instructor provided the 5.56, military providing the range (especially as they like bullet proof things!). Fascinating how easy it is to stop a 5.56 - much harder for 7.62.
 
Hello All,

Dave, I am glad you were paying attention. I can't think of a better addition to the discussion.

Gwynedd, There are LOTS of Yugoslav Mauser 98s on the market now. I believe the going price is in the $150 range. They are pretty close to a German K.98, but are about a half inch shorter in the receiver and thus not representative for my purposes, but as a launcher of 7.92 x 57 mm rounds, they should work well. I don't believe the 7.62 x 25 mm is a good substitute for a .357 Sig. Reasons are: The bullet is too small diameter and light and I don't believe they are typically loaded with the same hollow-point / soft-point assortment as you find in 9 mms. Yes, the .357 Sig is really a misnomer; It really is a high power bottle necked 9 mm with .355 diameter bullets. As such, I believe you can duplicate its performance with 125 grain bullets if you can find a lever action .357 Magnum carbine like a Marlin. I believe the Cowboy action folks tend to have those. The normal .357 Magnum out of a handgun probably won't achieve the velocity you want, but you can get the extra velocity out of a rifle / carbine length barrel. If the velocity is too high, back off a few yards. Now to think about it a little, your typical .357 Sig is coming out of a 4 inch barrel. If you find a 6 inch .357 revolver, you have effectively the equivalent of about a 7.5 inch auto pistol barrel and perhaps that would provide enough velocity. (I haven't checked the numbers.)

Skyferret, I've never loaded for Shotguns but do quite a lot of pistol and rifle reloading. You're going for the hyper velocity route. I go for the solid cast 450-550 grain .45 caliber bullets just loafing along at about 1400-1450 feet per second. This is not to say that I don't do higher velocity stuff, but I have never experimented with anything that would beat 4000 fps.

Hey Johnny, We already have the situation with folks in air conditioned rooms in the continental USA piloting RPVs over the war zones. Personally I would not recommend a FFL unless you understand the consequences: business hours, records keeping, potential BATF visits, etc.

- Ivan.
 
Good for him, Dave. That is taking the traditional plastic laminate idea into the most advanced realm of chemistry and physics before others have done it. I hope he is very successful with the idea. I would love to see him apply thin aluminum oxynitride layers in place of glass, if he is able to get it. http://www.livescience.com/technology/051018_new_glass.html

Dave Cumming said:
Reading this post with great interest. Over the last year i have been providing some firepower for a friend of mine who is developing better bulletproof glass. He used to be an ATO (I don't know the US translation but in English he was a bomb disposal officer). Retired, burnt out about 8 years ago and taken over the family chemical company. He was looking at using nano particles in plastics to improve the energy asorbtion between the sheets of glass for car windscreens. The glass does a good job of destabilising the bullet and the plastic polymer then absorbs more energy. Several layers of plastic and then some sheeting at the back to hold it all together. To pass the tests he had to put 5.56 and 7.62 nato rounds into the area without any fragments getting through and without losing too much visibility. I provided the 7.62 and a friendly Police Firearms instructor provided the 5.56, military providing the range (especially as they like bullet proof things!). Fascinating how easy it is to stop a 5.56 - much harder for 7.62.
Click to expand...
 
With the V-22, are you forced to look at repeat fire? If I remember this right... ceramic body armor plates are a one hit use. Kevlar and similar vests would be better for repeat hits, but probably not on identical points of impact...

With ceramics, we were talking today about using crystal changes in the material to actively repair cracks and fractures as they occur. Of course, EVENTUALLY, this will run out of material, and stop functioning, leading to a brittle failure.

Unfortunately, I don't think any of this would be terribly effective against RPG's, which I would venture to say are a far more realistic threat to low flying aircraft.
 
Thanks, Ivan.
I will have a look at the Mauser model that you mention and see if anyone in town has one. The maximum energy density of a 7.92 x 57 round is 89.2 Joules/mm^2 compared to 86.4 Joules/mm^2 for the 7.62 x 54R such as the Dragunov rifle uses. Good call. If the Navy and Marines want it and can sacrifice the extra weight for that level of protection, I will spring for it. BTW, .30-06 energy density is 83.8 J/mm^2, so it is not a player.
Insofar as the .357 Sig is concerned, the standard prescribes 6 hits with 125 grain, FMJ flat nosed at 1470 fps. http://www.ncjrs.gov/pdffiles1/nij/223054.pdf That equates to an energy density of 11.78 Joules/mm^2 . The 7.62 x 25 carries an energy density of 12.25 Joules/mm^2, so I would judge the smaller, faster round more potent against armor. It goes without saying that a hollow point round is very easy to stop in armor compared to a rounded or pointed solid projectile.
And finally, I don't want a Federal Firearms License or a Class III permit. I don't even shoot the rifles myself unless I have to. I already took three bullet ricochets from Russian 7.62's in my body so far doing this stuff. I just want to make armor that works, not shoot stuff. I don't enjoy that part. I enjoy it a lot less when I get shot.

Ivan said:
Hello All,

Gwynedd, There are LOTS of Yugoslav Mauser 98s on the market now. I believe the going price is in the $150 range. They are pretty close to a German K.98, but are about a half inch shorter in the receiver and thus not representative for my purposes, but as a launcher of 7.92 x 57 mm rounds, they should work well. I don't believe the 7.62 x 25 mm is a good substitute for a .357 Sig. Reasons are: The bullet is too small diameter and light and I don't believe they are typically loaded with the same hollow-point / soft-point assortment as you find in 9 mms. Yes, the .357 Sig is really a misnomer; It really is a high power bottle necked 9 mm with .355 diameter bullets. As such, I believe you can duplicate its performance with 125 grain bullets if you can find a lever action .357 Magnum carbine like a Marlin. I believe the Cowboy action folks tend to have those. The normal .357 Magnum out of a handgun probably won't achieve the velocity you want, but you can get the extra velocity out of a rifle / carbine length barrel. If the velocity is too high, back off a few yards. Now to think about it a little, your typical .357 Sig is coming out of a 4 inch barrel. If you find a 6 inch .357 revolver, you have effectively the equivalent of about a 7.5 inch auto pistol barrel and perhaps that would provide enough velocity. (I haven't checked the numbers.)
Personally I would not recommend a FFL unless you understand the consequences: business hours, records keeping, potential BATF visits, etc.

- Ivan.
Click to expand...
 
Military body armor today consists of two variants: the SAPI (small arms protective insert) plate and the ESAPI (enhanced SAPI). SAPI is a multi-hit B4C face design to withstand FMJ. ESAPI is technically good enough at one hit AP capability. They can take more in certain conditions.
In this project we have stricter boundary conditions, though. Again, the problem we face is power to weight ratio, and the contractor will tell us their needs and limits. I don't want to get specific on a board like this because I don't know who is reading it besides us. Suffice it to say that indeed there are more things than are dreamt of in use now. I just hope some of it works.


Pratt&Whitney said:
With the V-22, are you forced to look at repeat fire? If I remember this right... ceramic body armor plates are a one hit use. Kevlar and similar vests would be better for repeat hits, but probably not on identical points of impact...

With ceramics, we were talking today about using crystal changes in the material to actively repair cracks and fractures as they occur. Of course, EVENTUALLY, this will run out of material, and stop functioning, leading to a brittle failure.

Unfortunately, I don't think any of this would be terribly effective against RPG's, which I would venture to say are a far more realistic threat to low flying aircraft.
Click to expand...
 
Food for thought.

~S~ All,

EOD I think = ATO, not sure anymore.

I am told that there are speed limits that cannot be exceeded. The speed limit for muzzle velocity for firearms is said to be 2,000 km a second. That would be 6561679.790026247 feet per second. I am not sure what could fire a projectile at that speed, but I want one. I really have no idea what could stop that.

When I was young I could shoot birds out of the sky with a BB gun. Later it was targets at 1,000 yards without telescopic sites, using a M-14, 7.62 NATO round. You could fire the round and look through your spotter scope and see the vapor trail as the hot bullet moved through the cool air and into the target. That seamed to be a long time, but was probably 2 seconds +/-.

j:cost1:
 
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