Vehicle protection from artillery shells

[TheForwardObserver]

2 hours ago, shift8 said:

Let's not play dumb please. You made your opinion rather clear when you chastised Miller for having and opinion contrary to what you perceive as correct. 

Negative Shiftsworth, I encouraged miller to give us a story to establish his credibility after noting that for the last half year he's tirelessly repeated the same red flagged university of wikipedia garbage every time the issue comes up.  Maybe in your world he's an expert but not mine.  That is independent from my own personal opinion on what should happen re; arty and tanks.

Edited April 8, 2017 by TheForwardObserver

[HerrTom]

2 hours ago, shift8 said:

Right but this doesn't mean much. If you read the hard data later in the document, the number of perforations per shell per square foot are measured in the .01 and similar. The chances of a penetration is so low as to be more or less assured for practical purposes. 

All things being equal:

A BMP presenting its side to an artillery shell at 30 meters presents approximately 0.4 steradians.  Okay, I'll give you that - it's not a huge angular size.  But even at that, you have 0.6314 (from the data there) perforations per shell on this vehicle - those odds don't seem so insignificant under an artillery barrage.

Now P(H) isn't the same as P(K), which I can't really provide data on - but I think it's safe to say that a perforation has a chance to damage interior components.

If we take this shell and move it closer and closer to the vehicle, the solid angle will approach 2pi steradians as it lands directly next to the vehicle - 15x larger!  Even using the data from the 90 foot blasts, you can see that the number of fragment impacts are going to dramatically increase.  Unfortunately, they don't seem to have data of steel plates at anywhere closer than 90 feet, so I can't give hard-er numbers to give an idea of the penetrations you'll see per shell.  But we can reason our way to an educated guess:

Fragmentation hitting the target shouldn't change if the solid angle doesn't change (ignoring them hitting things or gravity and things like that).  So we can guess that the BMP will receive about 15x more hits as it gets closer to the vehicle.  

We can also get a rough guess as to the increase of penetration power by looking at the 1 1/4" aluminum plate they used in the phase I testing.  I'm going to do some math with this and see what I find.

Using an exponential fit to the data plus a scaling factor to match the aluminum plate with the steel plate performance at 90 feet (oddly enough it seems 1.25" of aluminum is roughly equivalent to 1/2" of steel. Cool! )

Edited April 8, 2017 by HerrTom
Plot!

[shift8]

22 minutes ago, TheForwardObserver said:

Negative Shiftsworth, I encouraged miller to give us a story to establish his credibility after noting that for the last half year he's tirelessly repeated the same red flagged university of wikipedia garbage every time the issue comes up.  Maybe in your world he's an expert but not mine.  That is independent from my own personal opinion on what should happen re; arty and tanks.

Negative Shiftsworth? Wut lol?

 You posted a loaded question back at Miller that implied in typical "holier than thou" fashion that anyone with opinion contrary to a certain reading of documents is a fool.

Your reply here only confirms without doubt that you were disagreeing with him. You can't have your cake and eat it too. 

[TheForwardObserver]

1 hour ago, shift8 said:

Negative Shiftsworth? Wut lol?

 You posted a loaded question back at Miller that implied in typical "holier than thou" fashion that anyone with opinion contrary to a certain reading of documents is a fool.

Your reply here only confirms without doubt that you were disagreeing with him. You can't have your cake and eat it too. 

Shiftsworth, you're not much of a mind reader are you?  Do please tell me which parts specifically about my opinions on the effects of arty versus armor that you disagree with.  I will wait.

EDIT:  maybe it was one of these posts that triggered you?  

I agree with Panzer and Miller in spirit-- HE-Quick is not the best tool in the box for doing the business against armor.  With that said I think the Abrams resiliency in-game could still be toned down a notch.

@IICptMillerII Just curious, are you under the impression that an Abrams in real life could sustain this many direct hits from 155 HE-quick and still function?

Edited April 8, 2017 by TheForwardObserver

[c3k]

Less vitriol and more facts would be good...if this thread will have any chance of staying unlocked.

 

[Artkin]

Must be those blast doors

[HerrTom]

33 minutes ago, Artkin said:

Must be those blast doors

 Haha! Pure depleted uranium, I hear!

I've continued to search through DTIC, and while I've found a lot of interesting things that I've saved (like a series of books on designing ammunition, including artillery shells) I haven't really found anything particularly useful on artillery fragments' effects on armor beyond the things I've already posted.

If only the USSR/Russian Federation maintained something like DTIC, then we might be able to see some reports on their artillery tests...

[IICptMillerII]

@TheForwardObserver

No, I am not a 13F, nor have I ever been in any of the 13 series MOS. I have never called for fires, or seen the effects in person of fires in real life. I have never attended artillery school or FO school. I have read pieces of the US Army field artillery manual (there are two, but I'm blanking on the FM designations at the moment. My apologies) but as you already know reading parts of a manual without proper instruction is nearly a waste of time. I also do not have a CIB, or a Purple Heart, and the last time I was pulled over was two years ago and I only got a warning. 

I put up plenty of sources in the other artillery threads. You quoted yourself from one of them. I'm stuck on my phone right now so going through those other threads to post my sources here is too much of a hassle. None of them were simple wiki drivel.

As for the 2002 report that keeps getting thrown around here, I would like to point out that one of the tests involved firing a BATTALIONs worth of artillery at a single mechanized infantry team. Said test resulted in over 50% of the mech inf team being destroyed if I remember correctly. Apologies if I misremembered. Fire a battalion of artillery against any stationary target and you're going to cause a lot of damage. In fact, if you fire a battalions worth of 155mm at an Abrams platoon in CMBS, you'll likely kill all 4 of them. I've done it myself. Again I cannot post results right now or run the test as I am away from my computer, but others here are more than welcome to try.

I agree with you, HE artillery is not the first asset/tool you should utilize against tanks. HE against APC/IFVs is generally effective at disabling or destroying them, usually enough to take them out of the immediate fight. I also agree with you that the amount of hits your Abrams shrugged off was excessive, and in real life would have likely resulted in a mission killed tank. 

The only argument that I have been "tirelessly repeating" is that HE is not the optimal weapon to use against armored targets, specifically tanks. There are a lot of ideas/opinions being thrown around in these threads. Some are arguing that artillery should be able to kill everything with just a few near misses, others are saying that the Abrams is too resilient to artillery. I agree with the latter, to an extent. 

I never meant to butt heads with you, mostly because I am in agreement with most of what you have said. 

If you have any more personal questions for me, you can drop me a PM. I'll be more than happy to talk with you one on one, but I would prefer to keep character assassination off the public forum. 

Edited April 8, 2017 by IICptMillerII

[Sgt.Squarehead]

3 hours ago, IICptMillerII said:

but I would prefer to keep character assassination off the public forum. 

No Comment. 

Edited April 9, 2017 by Sgt.Squarehead

[John Kettler]

TheForwardObserver,

Your thumbnail, which shows a tank which would likely be so pulverized it would take a lot of work to gather up the pieces so it could be scrapped, practically broke my brain when I saw it. In fact, I'm still processing what I saw and what my understanding of weapon effects tells me would likely happen. I see at least five direct hits on the ammo storage part of the turret. Offhand, I can conceive of no credible scenario, presuming fuze functioning, in which one strike wouldn't be enough to at the very least somewhat buckle, by blast alone, the blowout panel hit. The left one took something like four, and it's my considered opinion this would not only thoroughly distort the panel but allow direct ingress of blast and fragments. Worse, I see at least three hits in locations where they can attack the panels at their edges, places where significant torquing forces can be applied, ripping off the panel and almost certainly exploding the ammo within. One way or another, ammo goes up, and the tank's out of the fight.

As for the fighting compartment proper, I think the strike to the immediate left (looking from aft forward) of the TC's cupola, would, best case and then some, blow in close to half of the vision blocks, making the tank unfightable, not to mention what would happen to the poor TC--presuming the direct hit above him somehow didn't incapacitate or kill him. Realistically, I would expect the blocks to be blown in, together with scads of frags and lethal blast. K-Kill.  If that didn't suffice, there are several other hits other hits positioned to strike the cupola from other positions, and that's ignoring the direct hit on the cupola and a second on the loader's hatch. The wind sensor and anything else up there are gone (partial F-Kill and no comms at all; not sure if there's a Kill classification for no comms), and the CITV, presuming it's not simply ripped out by blast, is shredded and useless, likewise the integrated day sight and thermals. The tank, from the loss of all its primary sensors alone, would be an F-Kill in all but name, and it couldn't communicate, ether. Mission Kill or very nearly that. Since I can't see anything forward of the turret roof, all I can say is my opinion is that strikes landing on the glacis or turret face would likely have knocked out the gunner's last resort sight. If so, we now have 100% F-Kill and no comms. Mission Kill.

My assessment, based on a fair knowledge of weapon effects from historical studies, test shots, various reports, known combat damage spanning several wars and the JMEMs (including the rigorous 1967 SECRET level assessment of tanks destroyed in the 1967 war), is that one or two turret top hits would make the tank a Mission Kill right there, starting with deflagration or explosion in the ammo area. Let's say, though, somehow that doesn't happen. The impact next to the cupola and on the loader's hatch is going to put the tank out of the fight. Deem the more likely outcome the incapacitation or death of the turret crew. Anything sufficient to do that is going to wreck the interior of the turret, too. Effectively, K-Kill, minimum, 100% F-Kill. Again, tank's a Mission Kill. Summing up, I can conceive of no real world outcome which would leave a functioning tank, but many which would leave a K-Kill, Mission Kill, full or partial F-KIll and, in any case utterly unable to communicate via voice radio, digital comms, etc. Do they still carry signal flags?!

Would point out we don't have to argue this in a vacuum, either, for our Ukrainian de facto war correspondent extraordinaire Haiduk has provided us with pics of what happens with but a single turret top direct hit from a 120 mm class hit. The (forget exact model; T:64?) tank was repairable but was out of the fight, since the commander's station (right next to the hit) was wrecked, with a great gouge torn in the steel of the turret. Not sure about crew casualties. Tank was a Mission Kill in any event. To me, this speaks volumes about why the Russians have such confidence a single 122 mm Kitolov 2M hit suffices to destroy a modern tank. Bluntly put, from a real world perspective, your tank should be useless at incredibly best. Could I be wrong? Maybe. Perhaps panzersaurkrautwerfer, panzerleader et al. can somehow crushingly refute my, I believe, well founded conclusions. Can't conceive a design requirement for a tank to survive a direct hit from such a weapon, still less the 152/155 mm HE PD about whose effects we are debating. This is especially true since I know the original Bradley survivability requirement was 1 x 152 mm airburst at 18 meter HOB and zero crew compartment penetration. Not sure what it was for the Abrams, but expect it would've been similar. Have seen zero footage of any such test, if it occurred. 

Herr Tom,

Here are some reports which might advance the fragment penetration side of things.

Technical Report ABRL-02188

The Particle Dynamics of Fragment Penetration

James Dehn

September 1979

http://www.dtic.mil/dtic/tr/fulltext/u2/a077114.pdf

 

Accession Number : ADA086546

Title :   An Analytical Model of Kinetic Energy Projectile/Fragment Penetration

Descriptive Note : Final rept.

Corporate Author : ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Zook, John

PDF Url : ADA086546. (Link works. I checked)

Report Date : OCT 1977

Pagination or Media Count : 131

Abstract : The basis for an analytic model of kinetic energy projectile (fragment) penetration is described. It is based on an expression for the resistive force encountered by a projectile during penetration. The predictive capability of the model is compared to that of the Thor equation for residual velocity. Some conclusions are drawn concerning the penetration process. A tabulation of computer programs and sample output are included. (Author)

A STATISTICAL METHOD FOR THE EMPLOYMENT OF FRAGMENT HIT AREA IN PENETRATION EQUATIONS OR CODES

Presented on 12th International Symposium on Ballistics, San Antonio, Texas

Leon F. Galle

Division for National Defence Research TNO

The Netherlands

http://leongalle.com/Documents/Galle, L.F. A statistical method for the employment of fragment hit area in penetration equations or codes.pdf

There are more, but these should keep you out of mischief!

Regards,

John Kettler

 

 

Edited April 9, 2017 by John Kettler

[JUAN DEAG]

On 4/7/2017 at 7:20 PM, HerrTom said:

Here's (the only such, oddly enough) image of the BMP-1's armor thickness (Plus a Marder for fun and profit!)

If this is a BMP-1 shouldn't the rear doors be unarmored rather than 13mm? I may be wrong but I always thought that the rear doors of the BMP-1 were just fuel tanks.

[John Kettler]

JUAN DEAG,

The rear of the BMP is armored, but from a passenger survivability standpoint in the event of a hit, being on the other side of a RPG or RR penetrated fuel tank leaves a lot to be desired, which is why at least some Russian IFV units in Afghanistan stopped putting fuel in those rather vulnerable additional tanks and instead filled them with sand to increase protection. These BMPs then relied on the internal fuel tank alone. In reality, there were other threats, too, notably Dushka and 14.5 mm HMGs. For an extensive, and I do mean extensive, analysis of the armor protection of a BMP-2 and the associated armor metallurgy and a slew of tests, please see the Protection portion of the in-depth (talking more like bottom of the sea deep) coverage of the BMP-2 on Tankograd.

https://thesovietarmourblog.blogspot.my/2016/05/bmp-2.html

From that source comes this photo of what 122 mm HE PD can do in a direct hit. The 6 mm (534 BHN) turret roof is smashed in as if by a huge hammer. The steel of that roof is virtually identical to the ATI-500 MIL which figures in some of the tests referred to in this thread earlier.

The Tankograd T-72 analysis gives the minimum turret roof thickness as 20 mm and the maximum of 40 mm in the rear. This makes sense because the armor now has to increase as it becomes part to the rear armor and must be able to withstand  the attendant impact abuse. In light of what happened to the BMP-turret above from a direct hit by 122 mm HE PD, I have every reason to believe the 3 x (or more) thicker T-72 series turret roof would still suffer enormous damage. Granted, it likely wouldn't be as visually spectacular, but it would still wreck the turret or worse, resulting in a Mission Kill against the tank. Remember, the Mission Kill Haiduk showed was from a mortar, whose terminal approach angle is steeper than that of artillery projectiles, allowing more of the artillery shell's blast and frags to strike the turret roof. The big unknowns here are that I don't have the data on the Abrams turret roof and blowout panels handy, making it hard to nail down what those look like in terms of vulnerability. There have been documentaries which showed the primary plate being lowered into place, but I wasn't paying much attention to the thickness. Am pretty sure our Abrams types can give us a reasonable number and still avoid going to Ft. Leavenworth in chains!

https://thesovietarmourblog.blogspot.my/2015/05/t-72-soviet-progeny.html

Regards,

John Kettler

Edited April 9, 2017 by John Kettler

[HerrTom]

Thank you John for the plethora of information.  That fragment modelling one might take me a while to parse -  a lot of math, even for me!

[John Kettler]

Herr Tom,

You are most welcome. Happy to be able to advance your terminal effectiveness work. Glad someone can do the math--speaking as someone who couldn't hack Algebra II because of wrecked sequencing when learning traditional Math (was doing multiplication tables in elementary school and hit with the devastating to many numerical theory based, algebra like New Math) and had a kind of math dyslexia in which I kept screwing up sequence of operations. I never recovered from the former,and Algebra, since I had nothing to really hang my brain on (did in Geometry where I was great) was a nightmare. Naturally, this meant I learned neither Trigonometry or Calculus. Am therefore a kind of HIgher Math cripple. Thank goodness there are people like you who can crunch the numbers, else who knows what disasters might occur? 

Regards,

John Kettler

Edited April 9, 2017 by John Kettler

[Haiduk]

8 hours ago, John Kettler said:

for our Ukrainian de facto war correspondent extraordinaire Haiduk has provided us with pics of what happens with but a single turret top direct hit from a 120 mm class hit.

Hmmm... I don't recall a photo of TANK... But... May be you means this 1V13 from Avdiivka, which caught 120 mm mortar bomb or 122 mm arty shell ?

[Haiduk]

I just show several exampes of UKR vehicles, which were destroyed by fragments of close explosions. In most cases fragments set fire fuel or caused detonation of ammunition. This is photos form summer 2014, when our troops stay on the border and were shooting out from Russian territory with mortars, artillery and MLRS.

BTR-80, Marynivka border checkpoint. Despite on trench, fragments set fire APC and caused small detonation with moving of turret.

BMP-2, same location. I doubt what exactly happened, but looks like large fragment side hit and detonation.

T-64BV, same location - set fire and burned after artillery strike, but no direct hit.

There are a lot of photos on Lostarmor, but this is big piece of work to select armor, destroyed by arty shell fragments. I can say only one - any Soviet/Russian/Ukrainian tank will not survive direct hit of artillery shell 122 or 152 mm despite on ERA blocks on top. Side hull of tanks also vulnerable for big fragments of MLRS and shells - I wil try to find photo of LNR T-64, which was hit by close Grad explosion - several fragments penetrated side hull (ERA blocks doesn't react on fragments - its too slow relatively APFSDS) and kill tank commander. Tank remain operational after small repair. About light armor "fragment protection" nothing to say it is not exists. Side hulls of BTR 70/80 and BMP easy perforate even with 7,62 AP bullets for SVD, no words for 12,7 and higher.

Standard side armor protection of BTR-4E (not E1 with additional armor plates) has STANAG2 level and maintain protection from fragments of 155 mm shell, which explodes in 80 m  

Edited April 9, 2017 by Haiduk

[Haiduk]

I recall about one battle, which completely was solved by intensive artillery and MLRS strike. This is battle for Novosvitlivka in Aug 2014. UKR vehicles on positions were heavy bombarded, crews in panic withdrew, most tanks and light armor were destroyed.

This was BM Bulat. Direct hit

BMP-2 thought it hide well, but Russin shell thought else. Looks like fragments and wave of the shell, wich hit in nearby brick structure, hit vehicle and cause fire and detonation

In some meters from this one, other BMP-2 has found own end... Looks loke direct hit, but may be also detonation from fuel or ammunition hit by fragments.

 

Another direct hit in BM Bulat

RKhM-4 (NBC unit vehicle on base of BTR-80). Close explosion 120-122 mm. Turret has gone, vehicles knoked out. Later was burned.

One more BM Bulat. I can't say either direct hit or result of something big hit the building and initiated tank detonation

And piece of shugar on top. Juanuary of 2015, Hnutove. How look T-64 after direct hit with something heavy - I heard two versions 152 mm 2S5/2A36 Giatsynt shell or even 203 mm 2S7 Pion

Edited April 9, 2017 by Haiduk

[John Kettler]

Haiduk,

Bravo! You really came through, and in such a way I'm both shocked and with my middle abruptly in a knot. This ought to, at worst, give those who don't appreciate the power of a near miss or direct hit by artillery on a tank something to think about. The Abrams could well be tougher, but I really don't see how even one direct hit from 122 or 152 mm tube FA wouldn't at least badly damage it, if not kill it outright, especially on a tank where so much of it, seen from the perspective of an inbound shell, is turret, with most of that being turret roof. Would say, though, an advantage the Abrams has over Russian type tanks I've mentioned are those very substantial side skirts (fitted in game and for real in Europe with ERA as well), which stop most of what would otherwise strike the lower side hull.

If you can find it, would still love to see one you posted earlier (from Debaltseve, maybe), which was a close up of the turret top of a tank which took a 120 mm mortar strike right next to the commander's station. After seeing what you presented, am of the belief that tank didn't wind up like the one smashed as if by a hammer because of both the trajectory and the use by Russia, not of high tensile steel but more like iron for the casings of mortar projectiles, taking them pretty much out of play. Regarding the former, as anyone knows, most of what a artillery shell does goes sideways, and that's true for most of the blast, too, from what I've seen on lots of warhead test footage, the exception being, of course, shaped charges. 

Regards,

John Kettler

 

Edited April 9, 2017 by John Kettler

[Bydax]

11 hours ago, John Kettler said:

pics of what happens with but a single turret top direct hit from a 120 mm class hit. The (forget exact model; T:64?) tank was repairable but was out of the fight, since the commander's station (right next to the hit) was wrecked, with a great gouge torn in the steel of the turret. 

On 04.07.2015 at 8:17 PM, Bydax said:

Ukrainian T-64BV after a 120mm mortar round hit.

12 hours ago, John Kettler said:

Not sure about crew casualties.

On 04.07.2015 at 10:01 PM, Bydax said:

Crew rest nearby when tank was hit, they drive it to the rear but turret was "total loss".

 

[John Kettler]

Bydax,

Many thanks, for that was exactly the photo set (thought it was one image) I sought. From what I can see, it looks as though the detonation ripped away one hatch and two other items next to it, together with ripping the HMG right out of its mount. Wonder how well the sights worked after that smashing below from behind? Do you have any further details on damage to the tank and crew?

TheForwardObserver,

In my earlier assessment of likely outcomes for an Abrams hit as you described I somehow managed to forget to discuss glacis plate and turret front strikes, had such occurred to the real Abrams. Can't speak to BFC's modeling of such an event/s. If we posit the glacis plate is immune to both blast and frags (ignoring that tunnel going straight at the driver's viewing equipment and thence, under the turret), one obvious conclusion would be to expect the gun tube to wind up looking like a Swiss cheese and maybe bent, too. 100% F-Kill on the cannon. A lower turret face hit might upheave the turret (someone else would need to run the calculations), but certainly wouldn't improve its function and could greatly help the gun's chances of surviving via substantial masking of both blast and frag effects. An upper  turret face hit wouldn't provide that sort of masking, but if far enough displaced outward along the struck facet, would still help the cannon's prospects greatly. Obviously, a direct hit on the gun tube would be the end of the tube and likely the coax and backup sight, too. Net result in almost every case would be F-Kill on the main gun and likely the coax, too.

Regards,

John Kettler

 

 

Edited April 9, 2017 by John Kettler

[cool breeze]

Ok, can this thread perhaps be the final resting place of the line that tanks are mostly immune to artillery?

[Haiduk]

2 hours ago, Bydax said:

Ukrainian T-64BV after a 120mm mortar round hit.

Thanks! I didn't post this photo 100 %. What can I say ? Mortar shell has round head and slow speed of falling, so it capability to crack or penetrate tank top turret armor is close to zero, but if it will hit in hull top on engine area it can makes effect. Next. both sides uses 120 mm mortar shells of two types: 16 kg OF-843B with 1,4 kg of amatol (1,35 kg TTE) and 16,1 kg OF-36 with 3,6 kg of amatol. (3 kg TTE).

Compare this with bullet-type nose and higher speed of artillery shell, for example, 122mm 21,76 kg OF-462Zh with 3,67 kg of hexal /A-IX-2 (5,69 kg TTE). OF-462 claims 42 mm of steel penetration. 

So, we can conclude, that mortar round has lesser chance to destroy tank in direct hit, than 122 mm artillery shell.

Edited April 9, 2017 by Haiduk

[John Kettler]

Haiduk,

Given that PD for howitzers is presumably SQ, I wonder how much actual point impact force occurs before the casing disintegrates after the shell explodes? Anyone know?

cool breeze,

22 minutes ago, cool breeze said:

 

Ok, can this thread perhaps be the final resting place of the line that tanks are mostly immune to artillery?

 

Only if people pay attention and are willing to accept the evidence, which I deem incontrovertible and several, as being persuasive!

Regards,

John kettler

[TheForwardObserver]

Some recent instances of the BOSS ABRAMS effect.  I haven't paid particularly diligent attention to the numbers since the 4.0 upgrade, because the combination of loving the 4.0 upgrade and playing Steel Beasts as an RTS has in a sense dulled my zest for CM reform, but the numbers I have kept track of do differ slightly from my tests a year ago FWIW.  Has anything changed since then I don't know?  Regardless, I expect these outcomes 25 percent of the time-- which would be absolutely more than fine, if I were able to call for accurate fire missions without the need to adjust first (which would be a capability I would bind to the laser designator or Veteran+ Observers if I were making suggestions).  I recognize people like to go with EXCAL which is optimal for point targets, or when you have multiple observers that can coordinate their EXCAL missions on a group, but it's no way to deal with moving group targets, where you've planned an area mission based upon enemy rate of march and likely avenue of approach-- if I need to mass fire on a platoon of Abrams EXCAL just isn't the right tool, and the adjustment rounds cue enemy exodus.  Anyways.  These guys each had their own battery 6 converged sheaf laying into them for 6-7 minutes.

The missing ERA is just cosmetic.  

[John Kettler]

TheForwardObserver,

Do you by any chance have any sort of frag size and weight breakdown for when 155 mm HE PD detonates? Haidul talks about a heavy fragment ripping through the side of a BMP and setting it ablaze, which got me curious. Also, I recall an incident (during the SAE, maybe) in which a large frag from 155 mm HE PD, much to the surprise of the testers, speared right through the turret side (didn't go clean into it, but stuck partially into the interior, causing spall for sure) of what I recall as being an M60, though that may well have been a M46 or M47.  Any idea how I can get a copy of the full SAE? Would love to read it.

Regards,

John Kettler