One misunderstood, the other; wish we had?

Peregino,

She's a beater, bought her a while back when Arlington Ordnance was importing them back into the states. I use a M7A3 launcher and it makes things allot easier on everything including the shoulder. Now if I had an M8 for the carbine, then I would definately be worried. FM's from back then stated that RG's should only be fired in "emergencies" from it and especially so if you where using the folding stock. Either way, from the Carbine you were suppose to fire it from the ground only. You did this by using "Kentucky windage" and placing the Carbine's toe of the stock in the ground firmly. Some FM's will even tell you that you were to fire them with the heel and toe of the stock sideways in soft ground. On the folding version you placed the rear part of the receiver where it meets the stock on the ground. This makes you fire them from an "upside down" position on the rifle. M8's are running $250-300 for one. Guess their so high because there wasn't many made.

The little M7's commonly referred to as the "Vitamin Pill" gave you extra yardage when used in conjunction with HE, Smoke, AT, AP, & WP rounds. Can't use them on Streamers or Flares. The M7 was NEVER to be used on the Carbine.

I have been talking to our guys coming back from Iraq and asked them if they were allowed to use recovered RPG's for their own use while on patrol. All of them stated "No". When asked why, my one buddy (he was training the ING) stated that "we could use AK's ourselves but the ING's were the only ones to be in possession of them." Jeeez, they even took away all of his M67's before he started working with the ING. He ended up buying a few F1's from the black market outside of Baghdad for $3.00 a piece. Do we have a shortage of M67's out there?

[Peregrino]

Originally Posted by jbour13

Looking at MAB32's post spurred a question that I never knew how to ask and receive an answer. Since this board has the knowledge it may not hurt to ask.

The rifle grenade is the poor man's mortar and could also be used in the direct fire mode. But my question is, can a 40mm or 60mm mortar be trigger fired (safely) as a direct fire weapon?

Last duty assignment was in an infantry bn and I was told this, but never found anyone to back up this claim. I just wonder if that is one of those things they teach 11C's in AIT that is not in the book.

One of the funnest things I got to experiance while assigned to the unit was hanging with the bn mortars (81's) and riding the baseplate to settle it.

One way to keep a private occupied is ask him to count the rings on an 81mm mortar until he gets it right.

Small minds are easilly entertained. The fun part is the look on their face when you have to define "rings" after he's counted it 4-5 times only to have you tell him there are none. I've never encountered a 40mm mortar. The infamous Japanese "knee mortar" of WWII fame was small calibre but I don't remember the exact diameter. There is "direct fire" then there is "direct lay" two completely different actions commonly confused by the uninitiated. Trigger fire (the old M19 and the new "don't remember the #", Brit mortar we've had for about 20 years) mortars can be used either way. Both have a small base plate specifically for "hip shoots" (shooting in a hurry - not shooting from the hip). Direct lay is a common mode of employment, direct fire is usually an act of desperation or stupidity (personal opinion). I'm talking about infantry use - the Navy PBRs have a different type of mortar that is designed to be direct fired. There's also a type of Russian(?) mortar that was clip fed (5 rounds) and mounted in a wheeled vehicle that is designed for direct fire. Never seen one in person. IIRC somebody posted a video clip of a test fire with it mounted in a HMMV sometime last year. HTH - Peregrino

[jbour13]

So after I hijacked (slightly, sorry) back to the original idea.

AT-4's uses a directional gas jet warhead to penetrate the armor. Hot gas opens a hole, charge detonates inside to create spalling subsequently killing whatever is inside. Penetration 400mm of rolled homogenous armor (no countermeasures, reactive armor, etc). Warhead is 4lbs of HEAT.

RPG-7V's have a warhead that is 1mm larger and .6lbs more charge. It is a shaped charged warhead that explodes only once. I has a small metal core that burns through armor and has no explosive action after it penetrates armor. The core typically exits the other side of the APC, etc. Kinda like a dep uranium round. The heat created does the damage since there is no secondary (technically) explosion. It's penetration is the same as an AT-4 as long as it is a truely perpendicular shot. It's performance degrades with increased angle of engagment.

AT-4: self contained and private proof. More friendly to rough use and safer overall.

RPG-7V: multiple parts (launcher, motor, warhead, booster), takes practice to prep the round prior to firing and is not your friend once armed. Bumping it hard enough could cause a detonation.

This is what I don't know for sure. Once the RPG is armed for use, ie the motor is affixed to the warhead and locked into position, is there anyway to un-arm and take it down for future use?

Seen them, held them but never fired them. FOB 52 had a $hitload of weapons when I was in IZ. The S-2 of 2-5 was a infantry PL in my old BN and took me on a weapons fam. Interesting stuff.

Edited to add: I know jack,....TR smacked the sense into me below. Thanks TR.

[Peregrino]

jbour13 - You need to do a little more research before expounding on munitions and their effects. Especially shaped charges and why the AT-4 is a dual system. Your other questions can also be answered easily. Try "Jane's" for starters. Peregrino

[The Reaper]

Both the AT-4 and the RPG use a shaped charge to penetrate the target. The rounds are both free-flight, fin-stabilized, rocket-type.

Both use a Point Initiated-Base Detonated firing system for the warhead.

The molten liner is detonated from the rear by the noze located fuse upon contact with a hard surface and "burns" through the target with a penetrator it is reformed into, known as and looking somewhat like a carrot.

The shaped charge function is technically referred to as the Monroe effect.

Penetration and diameter of the penetration is a factor of liner depth, angle, and composition, compounded by optimization for the desired target.

Most U.S. shaped charges designed for armor penetration use a copper liner or other metal. Many of the preformed shaped charges (like the 15 and 40 lb. Shaped Charges) for breaching earth or concrete use a glass liner.

The main difference between the two weapons is whether you want a re-usable launcher and the different features of each. Both are equally effective. IMHO, the AT-4 is a repackaged 84mm Carl Gustav round into a disposable, single-shot system.

TR

[jbour13]

Originally Posted by Peregrino

jbour13 - You need to do a little more research before expounding on munitions and their effects. Especially shaped charges and why the AT-4 is a dual system. Your other questions can also be answered easily. Try "Jane's" for starters. Peregrino

I got the info from FAS.org The info for the RPG-7V came from a TRADOC bulletin:

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

AT-4 is from:

http://www.fas.org/man/dod-101/sys/land/at4.htm

May be bad info. I'd like to know what info I re-gurgitated that is incorrect.

I don't have the money for Jane's, wish I did though.

[The Reaper]

Originally Posted by jbour13

I got the info from FAS.org The info for the RPG-7V came from a TRADOC bulletin:

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

AT-4 is from:

http://www.fas.org/man/dod-101/sys/land/at4.htm

May be bad info. I'd like to know what info I re-gurgitated that is incorrect.

I don't have the money for Jane's, wish I did though.

jbour, you have a tendency to shoot before aiming.

The warhead info you regurgitated say the same thing about both rounds, except that there is no secondary explosion by the AT-4. It is a standard 84mm HEAT round. The PG-7VR warhead for the RPG has a secondary explosive charge to assist in defeating reactive armor.

The spall is part of the target armor which is heated and fragged off the interior. The carrot also comes through and is an additional source of kinetic and pyrotechnic effects.

You are also wrong about the warhead weights. You cited the weights of the rockets themselves.

The RPG-7 is in no way like a depleted uranium round except that they are both munitions.

The penetration of both rounds is reduced as the angle increases.

Neither weapon is private proof, but the RPG-7 is more robust. The AT-4 is not necessarily "More friendly to rough use and safer overall."

You need to separate your characterizations of the RPG-7 launcher from that of the various PG-7 warheads it can fire. All of the examples I have used can be decocked , the round is merely placed in the launcher prior to use and is frequently carried that way (without cocking the launcher).

Would you like for me to look for additional errors in your post?

TR

[Peregrino]

Originally Posted by jbour13

I got the info from FAS.org The info for the RPG-7V came from a TRADOC bulletin:

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

AT-4 is from:

http://www.fas.org/man/dod-101/sys/land/at4.htm

May be bad info. I'd like to know what info I re-gurgitated that is incorrect.

I don't have the money for Jane's, wish I did though.

You misquoted your sources - both rounds function identically. The charge does not detonate inside the target. Spalling is a result of the initial armor penetration. TR's explanation is complete and correct. And in fairness I commented too quickly. The AT-4 is not a dual charge. IIRC that's only the larger missles. (I see TR is already on this - so I'll quit now.) Peregrino

[jbour13]

QP's, Thanks for the corrections, I mis-interpereted the info. I'm not a munitions guy and read it as being a primary explosion designed to open the armor and a follow-on detonation to create the spalling to destroy the intended target. Just trying to understand, not trying to dig myself in. I see the bottom and would like to clarify my post. I'll limit myself to questions on the effects then.

I don't mind if you pick apart the post TR, I would actually enjoy the constructive criticism and know if what I'm reading is correct and how to best educate myself and others. It's essentially my job to understand the capabilities of these weapons systems. You're the ones that teach HN troops the right from wrong, and I'm just as ignorant to the capabilities. I just don't have the ability to decipher all of the complicated terminology that is going to affect how people move on the battlefield.

By private proof I should have said because it has pictures and instructions on the AT-4 telling you how to employ it (effectively with no training....probably not). Can you dispell the rumor that an RPG warhead is not as sensitive to bumping and detonation as some have led me to believe. I'd like to know since we (generalized troops) may come along them on the battlefield and have to move them. General rule should apply, don't touch if you don't know, but it'd be good info if the munition/weapon posed a continued threat to troops. Especially if you had to pick-up and move and didn't want it to recirculate back into enemy inventory.

And along the lines of Dep Uranium rounds, I understand the basic differences. Just wanted to point out that the action of the rod going through the other side of the APC like a dep round would. I know the radioactive issues with dep rounds put it completely into a different category. More appropriate analogy could have been something like the old 30.06 AP rounds having a tungsten core. Don't know if that is more appropriate.

I'll stop bugging you QP's and try to break down the info to my simple minded standard and educate myself.

Thanks for the info so far.

V/R
SGT B

[Air.177]

Originally Posted by jbour13

QP's, Thanks for the corrections, I mis-interpereted the info. I'm not a munitions guy and read it as being a primary explosion designed to open the armor and a follow-on detonation to create the spalling to destroy the intended target. Just trying to understand, not trying to dig myself in. I see the bottom and would like to clarify my post. I'll limit myself to questions on the effects then.

I don't mind if you pick apart the post TR, I would actually enjoy the constructive criticism and know if what I'm reading is correct and how to best educate myself and others. It's essentially my job to understand the capabilities of these weapons systems. You're the ones that teach HN troops the right from wrong, and I'm just as ignorant to the capabilities. I just don't have the ability to decipher all of the complicated terminology that is going to affect how people move on the battlefield.

By private proof I should have said because it has pictures and instructions on the AT-4 telling you how to employ it (effectively with no training....probably not). Can you dispell the rumor that an RPG warhead is not as sensitive to bumping and detonation as some have led me to believe. I'd like to know since we (generalized troops) may come along them on the battlefield and have to move them. General rule should apply, don't touch if you don't know, but it'd be good info if the munition/weapon posed a continued threat to troops. Especially if you had to pick-up and move and didn't want it to recirculate back into enemy inventory.

And along the lines of Dep Uranium rounds, I understand the basic differences. Just wanted to point out that the action of the rod going through the other side of the APC like a dep round would. I know the radioactive issues with dep rounds put it completely into a different category. More appropriate analogy could have been something like the old 30.06 AP rounds having a tungsten core. Don't know if that is more appropriate.

I'll stop bugging you QP's and try to break down the info to my simple minded standard and educate myself.

Thanks for the info so far.

V/R
SGT B

I'm no munitions expert, but I was raised by AM. It is my understanding that the standard RPG round is of the HEAT type. No "Rod" to speak of is present. The outer housing of the projo is usually stamped sheet metal, and there may or may not be a metal (Copper usually) liner in the inverted cone on the nose end of the charge.

I could be mistaken though

[jbour13]

Originally Posted by Air.177

I'm no munitions expert, but I was raised by AM. It is my understanding that the standard RPG round is of the HEAT type. No "Rod" to speak of is present. The outer housing of the projo is usually stamped sheet metal, and there may or may not be a metal (Copper usually) liner in the inverted cone on the nose end of the charge.

I could be mistaken though

On page 7 of the FAS.org site for the RPG round it says small metal core is formed after the warhead is detonated.

I stand corrected.

[The Reaper]

If that is your job, you need more training than you are going to find on the internet.

I have seen a lot of guys using RPGs who I do not think could read the instructions on the AT-4.

I have seen a lot of beat up PG-7s, none that I am aware of have failed to function as designed. The nose cone is hollow on the front half, with just the piezo-electric initiator and its wires inside, and the fuze usually has a plastic cap on it as shipped.

The back half of the warhead contains the detonator, and the shaped charge with liner. Probably 75% of the warhead is empty space for standoff. The "stick" behind the warhead contains the propellant and is an attachment point for the fins.

A HEAT round like the rockets you refer to is a chemical energy round. The DU, sabot, and AP rounds are examples of kinetic energy penetrators. You cannot launch a kinetic projo from your shoulder fast enough to penetrate modern armor, hence the fact that all shoulder fired AT rounds I am aware of are of the shaped charge variety.

The odd thing about the PG rockets is that they are very succeptible to winds, and that unlike most other rockets, they turn INTO the wind, so windage is reversed.

Next time you require this much info, it will cost you beer.

TR

[jbour13]

Originally Posted by The Reaper

If that is your job, you need more training than you are going to find on the internet.

I have seen a lot of guys using RPGs who I do not think could read the instructions on the AT-4.

I have seen a lot of beat up PG-7s, none that I am aware of have failed to function as designed. The nose cone is hollow on the front half, with just the piezo-electric initiator and its wires inside, and the fuze usually has a plastic cap on it as shipped.

The back half of the warhead contains the detonator, and the shaped charge with liner. Probably 75% of the warhead is empty space for standoff. The "stick" behind the warhead contains the propellant and is an attachment point for the fins.

A HEAT round like the rockets you refer to is a chemical energy round. The DU, sabot, and AP rounds are examples of kinetic energy penetrators. You cannot launch a kinetic projo from your shoulder fast enough to penetrate modern armor, hence the fact that all shoulder fired AT rounds I am aware of are of the shaped charge variety.

The odd thing about the PG rockets is that they are very succeptible to winds, and that unlike most other rockets, they turn INTO the wind, so windage is reversed.

Next time you require this much info, it will cost you beer.

TR

I'd much rather know and be broke from buying rounds than taking rounds and buying it big time.

I don't drink so you'll have to pick up the slack, horrible...I know.

[The Reaper]

Originally Posted by jbour13

On page 7 of the FAS.org site for the RPG round it says small metal core is formed after the warhead is detonated.

I stand corrected.

That is the molten "carrot" I referred to.

If you are going to acknowledge your errors individually, this is going to take a lot of time.

It does not normally overpenetrate a hard target unless is is thin skinned. It loses heat and energy very quickly during penetration.

The holes are also very small in diameter, the exact size is again, to some degree a design function of the diameter, depth, and liner of the charge.

TR

[DanUCSB]

Originally Posted by The Reaper

Next time you require this much info, it will cost you beer.

Hell, does this mean I can just buy a couple of kegs and sit down and learn indefinitely?

Sounds like the best deal I've seen since W-M started selling his book.