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Tapered Thickness of Panther Mantlet


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The chin mantlet would be much more vulnerable than the rounded mantlet, since the effective thickness of the chin is slightly over 100mm on most areas. Once we have the tapered thicknesses over the rounded mantlet we can compare effective thicknesses over the chin area.

The chin is actually sloped somewhat. But even more important, it covers an area that is already armored. That is the area under the mantlet which is part of the turret front.

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Originally posted by Mr. Tittles:

The chin mantlet would be much more vulnerable than the rounded mantlet, since the effective thickness of the chin is slightly over 100mm on most areas. Once we have the tapered thicknesses over the rounded mantlet we can compare effective thicknesses over the chin area.

The chin is actually sloped somewhat. But even more important, it covers an area that is already armored. That is the area under the mantlet which is part of the turret front.

The probability of a round striking the turret front armor under the mantlet is in question, since the glacis protrudes upward over the hull top and rounds striking that extension, even by a little bit, would be sent upwards.

The existence of 100mm relatively straight up and down armor in an area that previously was highly sloped is something that will be analyzed in detail when we finish our spreadsheet model.

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Scaling and measuring off the chin mantlet drawing posted at the beginning of this thread, found the following info:

1. chin mantlet appears to be same height as rounded mantlet, 2' tall or 0.610m

2. starting from top edge of mantlet and working down (angle is measured from vertical, number in brackets is equivalent vertical resistance against 17 pdr APCBC hits):

UPPER HALF OF MANTLET

85 degrees, 20.6mm thick (143mm)

80 degrees, 27.3mm (165mm)

75 degrees, 34.2mm (172mm)

70 degrees, 41.2mm (169mm)

65 degrees, 48.0mm (168mm)

60 degrees, 54.5mm (155mm)

55 degrees, 60.6mm (145mm)

50 degrees, 66.2mm (132mm)

45 degrees, 71.3mm (123mm)

40 degrees, 75.9mm (115mm)

35 degrees, 79.9mm (108mm)

30 degrees, 83.4mm (103mm)

25 degrees, 86.5mm (99mm)

20 degrees, 89.2mm (97mm)

15 degrees, 91.7mm (96mm)

10 degrees, 94.1mm (96mm)

05 degrees, 96.7mm (97mm)

00 degrees, 99.5mm (100mm)

BOTTOM HALF OF MANTLET

00 degrees, 99.5mm (100mm)

05 degrees, 96.7mm (97mm)

10 degrees, 94.1mm (96mm)

15 degrees, 91.7mm (96mm)

20 degrees, 89.2mm (97mm)

25 degrees, 86.5mm (99mm)

10 degrees, 105mm flat area (107mm)

10 degrees, 110mm flat area (112mm)

10 degrees, 319mm flat area at very bottom (334mm)

17 pdr APCBC penetrates the following vertical thicknesses:

100m, 174mm

250m, 170mm

500m, 163mm

750m, 156mm

1000m, 150mm

1250m, 143mm

1500m, 137mm

The mantlet is far from 100mm thick everywhere.

The chin mantlet area is vulnerable to quite a few guns and ammo where the rounded mantlet would be fairly safe, with the chin mantlet making up the area where the rounded angles varied from 25 degrees to 85 degrees.

What the above analysis does not consider is that the upper edges would offer relatively low resistance to 17 pdr APCBC, which would be made even lower by edge effects, but the round might not have sufficient time to push out a plug and start to drive downward before it reached the end of the mantlet.

There also are various underlying materials at the edges of the mantlet which would add to the overall resistance, and there are the edges of turret front.

[ September 15, 2004, 03:46 AM: Message edited by: lorrin ]

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One interesting aspect of the Panther mantlet resistance is the ineffectiveness of the M10 and Sherman 76mm guns against the mantlet with APCBC. Early M10 combat against Panthers in Normandy resulted in a report that the only penetrations were against the ball machine gun mount and a ricochet onto the hulltop from the mantlet.

Nothing against the mantlet itself even though the resistance is far below the 76mm APCBC penetration at 250m (121mm vertical penetration at 250m).

This suggests shatter gap, where the round just couldn't do it against armor that it should have routinely defeated because of damage from having too much penetration.

The U.S. 76mm APCBC round had a rapid decrease in hardness from nose to main body. The theory is that when the 76mm round hit armor that it overpenetrated within a certain ratio the back force from rapidly accelerating armor could cause the 76mm round to bulge out between nose and main body, and then shatter.

How else would one explain the inability of the M10 and Sherman hits to defeat the mantlet armor? (rhetorical question).

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The remaining data needed to analyze the Panther mantlet is the tapering thicknesses of the rounded mantlet. It would be convenient if the thicknesses varied with angle in the same manner as the upper mantlet area for the chin design.

Any drawings out on the fully rounded mantlet thickness variations with angle?

Thanks.

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Hey Mr. Tittles smile.gif

I collected and scanned those pix while researching the question of the Panther mantle armour for CMAK beta as a fellow player raised the question "Why was his Panther's dying from T-34/85 hit's on the mantle area" in the CMHQ chat area a while back.

Being the curious type with too much time on my hands i devleved into it.

The "reinforced" mantle pix is found in the "Achtung Panzer- Panther" book that was published in japan. Its the ONLY time i have seen such a photo.

I was able to ask H.L.Doyle his opinion on the matter.He told me that both he and Thomas Jentz have never seen any documentation in regards to introducing such a "interim" solution and put it down too two possibilities.

The Panther mantle's were made by several firms. These were castings made using sand molds.

1st possibility is that the strenghtened" or "reinforced" mantle is a one off that was utilised due to the dire war material situation during the latter course of the war.

2nd is that this particular firm had trouble with its sand molds , causing it( the firm ) to alter the mold in some was so as the mantle could be cast successfully.

He also informed me that in some photo's of the cast mantle's you might see what looks like a saucer shaped "plug-end" somewhere on the mantle. This at first may look like a field repair job. What in fact it was is a "leak" in the mold during casting that left a big bump. which was later sanded/milled down.( Just read that Krupp was ordered in August 1943 to remove such protrusions from the mantle face - the appeared either side of the gun.)

The casting of the mantle's required some milling to the back of the mantle.. this was only done in the area that would receive the gun cradle.

As regard's to standards... the German firms did operate under the spec's of up to + or - 10mm in armour tolerance.

Regards

Måkjager

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The effective resistances I posted for the Panther chin mantlet were not modified for cast effects, which renders the armor less resistant than rolled armor. Tonight or tomorrow I will post the effective resistances to 75mm and 76.2mm ammunition which include cast deficiency modifiers.

The effective resistances to 6 pdr APCBC after cast modifiers will also be discussed relative to some British firing tests that were conducted during the war.

The thickness of the trunnion mounts on the two drawings scale out to 129mm and 138mm, while our book measurements from drawings came to 125mm and 135mm.

The trunnion mounts make up an area on the mantlet that is small. The mount to the left of the coax MG opening extends from the hole all the way to almost the left edge of the mantlet. The height of the mount is about 40% of the total mantlet height.

The trunnion mount to the right of the gunner vision opening is slightly to the right of the hole and is the same height as the left mount.

Each trunnion mount makes up about 9% of the mantlet width, so figure about 17% of the mantlet width at the center is trunnion mount with 125mm to 135mm thickness which extends for about 20% of the height above or below centerline.

If most shots bunch up towards the centerline the trunnion mount hit rate on lateral scatter would be somewhat less than the share of the mantlet width.

The drawing that Robert Livingston prepared for our book shows a narrow 90mm thick mantlet strip to the immediate right and left of the trunnion mounts which extends to the edge of the mantlet.

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Could the actual shape of the armor reinforce its strength? This is the egg shell effect. Eggs are very strong against attack from outside but easily broken from inside.

AS a AP penetrator tries to punch a plug through armor that is rounded aggresively, like the panther mantlet, it is being resisted by not only the armor directly in its path, but also by the armor in the immediate sides. Its sort of the arch effect on a bridge.

From the numbers, it would appear that the mantlet would not resist attacks like it did. Even the US 90mm AP (M77) round had a tougher time on the mantlet than the strait up turret front 110mm.

Mycenius..

8) 90mm Gun, M1A1, AA

AP M77 will penetrate front glacis slope plate up to 600 yards, the gun mantlet up to 1,000 yards and the turret up to 1,500 yards.

[ September 15, 2004, 07:39 AM: Message edited by: Mr. Tittles ]

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Originally posted by lorrin:

One interesting aspect of the Panther mantlet resistance is the ineffectiveness of the M10 and Sherman 76mm guns against the mantlet with APCBC. Early M10 combat against Panthers in Normandy resulted in a report that the only penetrations were against the ball machine gun mount and a ricochet onto the hulltop from the mantlet.

Nothing against the mantlet itself even though the resistance is far below the 76mm APCBC penetration at 250m (121mm vertical penetration at 250m).

This suggests shatter gap, where the round just couldn't do it against armor that it should have routinely defeated because of damage from having too much penetration.

The U.S. 76mm APCBC round had a rapid decrease in hardness from nose to main body. The theory is that when the 76mm round hit armor that it overpenetrated within a certain ratio the back force from rapidly accelerating armor could cause the 76mm round to bulge out between nose and main body, and then shatter.

How else would one explain the inability of the M10 and Sherman hits to defeat the mantlet armor? (rhetorical question).

It could also be from the APHE detonating before penetrating. I think this problem effected US 75mm/76mm (APHE) and 90mm(M82).

Shatter gap and predetonation would basically fail the projectile in the same manner. The only conclusive shatter gap would be a non-HE AP round (solid shot).

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I would guess the mantlet was made as follows:

1. Pour molten metal into cast with gun tube protector at the top (the part the gun protrudes through).

2. Remove from mold and machine the gun tube hole to spec.

3. Machine MG and sight ports and check for minimum acceptable 100mm depth after drilling holes. This assures thickness at two points (thinnest points perhaps).

4. Attach lifting eyes.

5. Machine back of mantlet to accept gun cradle. Drill trunnion bolt holes.

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Originally posted by Mr. Tittles:

</font><blockquote>quote:</font><hr />Originally posted by lorrin:

One interesting aspect of the Panther mantlet resistance is the ineffectiveness of the M10 and Sherman 76mm guns against the mantlet with APCBC. Early M10 combat against Panthers in Normandy resulted in a report that the only penetrations were against the ball machine gun mount and a ricochet onto the hulltop from the mantlet.

Nothing against the mantlet itself even though the resistance is far below the 76mm APCBC penetration at 250m (121mm vertical penetration at 250m).

This suggests shatter gap, where the round just couldn't do it against armor that it should have routinely defeated because of damage from having too much penetration.

The U.S. 76mm APCBC round had a rapid decrease in hardness from nose to main body. The theory is that when the 76mm round hit armor that it overpenetrated within a certain ratio the back force from rapidly accelerating armor could cause the 76mm round to bulge out between nose and main body, and then shatter.

How else would one explain the inability of the M10 and Sherman hits to defeat the mantlet armor? (rhetorical question).

It could also be from the APHE detonating before penetrating. I think this problem effected US 75mm/76mm (APHE) and 90mm(M82).

Shatter gap and predetonation would basically fail the projectile in the same manner. The only conclusive shatter gap would be a non-HE AP round (solid shot). </font>

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Revised post based on additional and new information, such as incorporation of cast deficiency compared to rolled armor and effective resistance against 6 pdr APCBC:

Scaling and measuring off the chin mantlet drawing posted at the beginning of this thread, found the following info:

1. chin mantlet appears to be same height as rounded mantlet, 2' tall or 0.610m

2. starting from top edge of mantlet and working down (angle is measured from vertical, number in brackets is equivalent vertical resistance against 6 pdr/17 pdr APCBC hits):

UPPER HALF OF MANTLET

Rounded Areas

85 degrees, 20.6mm (135mm/117mm)

80 degrees, 27.3mm (156mm/137mm)

75 degrees, 34.2mm (163mm/144mm)

70 degrees, 41.2mm (162mm/144mm)

65 degrees, 48.0mm (160mm/144mm)

60 degrees, 54.5mm (146mm/135mm)

55 degrees, 60.6mm (139mm/126mm)

50 degrees, 66.2mm (126mm/117mm)

45 degrees, 71.3mm (117mm/111mm)

40 degrees, 75.9mm (109mm/105mm)

35 degrees, 79.9mm (103mm/98mm)

30 degrees, 83.4mm (98mm/95mm)

25 degrees, 86.5mm (95mm/91mm)

20 degrees, 89.2mm (92mm/90mm)

15 degrees, 91.7mm (91mm/89mm)

10 degrees, 94.1mm (94mm/90mm)

05 degrees, 96.7mm (94mm/91mm)

00 degrees, 99.5mm (96mm/94mm)

BOTTOM HALF OF MANTLET

Rounded Areas

00 degrees, 99.5mm (96mm/94mm)

05 degrees, 96.7mm (94mm/91mm)

10 degrees, 94.1mm (94mm/90mm)

15 degrees, 91.7mm (91mm/89mm)

20 degrees, 89.2mm (92mm/90mm)

25 degrees, 86.5mm (95mm/91mm)

Flat Areas at Bottom of Chin Mantlet

10 degrees, 105mm flat area (105mm/102mm)

10 degrees, 110mm flat area (111mm/108mm)

10 degrees, 319mm flat area at very bottom (334mm)

6 pdr (HV gun with longer barrel) and 17 pdr APCBC penetrate the following vertical thicknesses:

100m, 115mm/174mm

250m, 110mm/170mm

500m, 103mm/163mm

750m, 96mm/156mm

1000m, 90mm/150mm

1250m, 84mm/143mm

1500m, 78mm/137mm

The mantlet is far from 100mm thick everywhere.

The chin mantlet area is vulnerable to quite a few guns and ammo where the rounded mantlet would be fairly safe, with the chin mantlet making up the area where the rounded angles varied from 25 degrees to 85 degrees.

What the above analysis does not consider is that the upper edges would offer relatively low resistance to 6 pdr and 17 pdr APCBC, which would be made even lower by edge effects, but the round might not have sufficient time to push out a plug and start to drive downward before it reached the edge of the mantlet.

There also are various underlying plates at the edges of the mantlet which would add to the overall resistance, as well as turret front edge which underlies the mantlet at the edges.

British firing tests with 6 pdr APCBC against the Panther mantlet resulted in many penetrations at a wide variety of angles, something that should not have occurred if the mantlet were of a uniform 100mm thickness. The estimates for rounded mantlet area resistance to 6 pdr APCBC shows that penetrations at 500m would be possible at impact angles from 0 degrees to 30 degrees with 50% probability or better, and to 45 degrees with a low chance.

The ability of 6 pdr APCBC to penetrate the curved mantlet areas at impact angles of 30 degrees or greater means that more than half of the total area of the curved mantlet is vulnerable.

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Scaling off four Panther mantlet drawings for the rounded areas (2 drawings for chin mantlet, 2 drawings for fully rounded), and averaging the thickness estimates at each angle, results in the following figures by impact angle:

impact angle/thickness/cast deficiency/vertical equivalent resistance (cast deficiency and resistance vs 17 pdr APCBC):

00 degrees/100mm/0.95/100 x 0.95 = 95mm rolled vertical plate

05 degrees/98mm/0.94/93mm x 0.94 = 93mm

10 degrees/97mm/0.94/99mm x 0.94 = 93mm

15 degrees/94mm/0.94/98mm x 0.94 = 92mm

20 degrees/91mm/0.93/99mm x 0.93 = 92mm

25 degrees/88mm/0.93/101mm x 0.93 = 94mm

30 degrees/84mm/0.92/103mm x 0.92 = 95mm

35 degrees/81mm/0.92/110mm x 0.92 = 101mm

40 degrees/78mm/0.91/118mm x 0.91 = 107mm

45 degrees/72mm/0.90/124mm x 0.90 = 112mm

50 degrees/67mm/0.89/134mm x 0.89 = 119mm

55 degrees/63mm/0.89/150mm x 0.89 = 134mm

60 degrees/55mm/0.87/156mm x 0.87 = 136mm

65 degrees/48mm/0.86/168mm x 0.86 = 144mm

70 degrees/40mm*/0.85/

75 degrees/33mm*/0.84/

80 degrees/26mm*/0.83/

85 degrees/16mm*/0.81/

Note:*-mantlet edge area over internal armor extension

Against 6 pdr APCBC at 30 degrees impact, the estimated effective vertical resistance would equal 84mm x 1.26 slope effect x 0.94 cast deficiency = 99mm of rolled vertical plate.

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http://www.geocities.com/mycenius/

http://www.100thww2.org/support/77657mm.html

If the Panther mantlet was so vulnerable to 57mm fire, why would these reports not note it?

Heres some interesting reading about 57mm use against a Panther. Note the lucky hit is not a mantlet bounce but a turret ring hit.

On this day an excited GI came running up to our position and told us to get the gun back down the road a hundred yards or so as a Panther was sitting out in the open. We were able to balance the gun so that it could be hand wheeled short distances. This we did. When we swung it off of the road we rolled it into a shallow depression beside the road. That lowered our profile to about chest height. Within seconds we had a round chambered and fired. That one caroomed off the turret. The next one had to be one of the luckiest shots of the war. It hit on a narrow ring between the turret and hull, which the turret rotated on.

The shot locked the turret so that the only way the tank could traverse its gun was to rotate the entire tank. This they did. But we were not a very big target, so they never saw us. Ask any tanker and he will tell you that a tank that is "buttoned up" is stone deaf and about 90% blind. We hurriedly poured about 5 more rounds into the Panther. One caused him to throw a track so he was unable to escape. At that point the Panther crew started to bail out. We had gotten our kill!

http://www.thetroubleshooters.com/history358.html

[ September 17, 2004, 08:48 AM: Message edited by: Mr. Tittles ]

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U.S. Army Test No.1

Report on Comparative Firing Program Witnessed at Shoeburyness, Essex, 23 May 1944 by U.S. Army Headquarters ETO representatives.

http://www.geocities.com/mycenius/

The 76mm M62 in this test seems to show that it could hole (PTP-projectile passes through) 100mm 0f RHA at 500m. It actually outperforms the 'new' 90mm M82 APHE rounds (which seem to predetonate). Note that the BDF does NOT go off in the M62 round. That is, it not only does not experience shattering, it does seem to exhibit fuse failure.

In this test...U.S. Army Test No.2

Firing Tests conducted 12-30 July 1944 by 1st U.S. Army in Normandy.

7) 3-inch Gun, M5, mounted on Motor Carriage, M10

a) APC M62, w/BDF M66A1 will not penetrate front glacis slope plate at 200 yards. Will penetrate gun mantlet at 200 yards and penetrate sides and rear of the 'Panther' Tank up to 1500 yards.

B) AP M79 will not penetrate the front slope plate or the mantlet at 200 yards. It holds no advantage over APC M62 ammunition w/BDF M66A1.

So there appears to be something beyond the rexford crunched numbers going on.

The 76mm M62 round does not shatter at 500m against RHA. Is cast armor so much harder that it causes shatter? If the M62 round DOES penetrate the panther turret at 200m, why not 500m?

Why is the Panther turret inferior to the mantlet when fired on by 90mm M77 AP ammo?

The evidence does not support rexford's calcs. the mantlet does not appear to be as weak as he would imply.

[ September 17, 2004, 10:09 AM: Message edited by: Mr. Tittles ]

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Perhaps theres a clue in the U.S. Army Test No.2

Firing Tests conducted 12-30 July 1944 by 1st U.S. Army in Normandy.

The M79 76mm round clearly is inferior to the M62 76mm round against the Panther front. The M79 round is just a heat treated slug (AP round) and does very well against homo armor. In fact, better than the M62 round will. But it is inferior to the M62 when attacking face hardened armor!

So does the cast mantlet act like face hardened armor? Is it possible to face harden the mantlet after it has been machined/drilled/etc?

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The details of shatter gap explain the 76mm APCBC results.

To shatter fail a round must overpenetrate the armor it hits by a certain ratio, and at 500 yards against 100mm at 30 degrees that ratio was not attained (penetration divided by effective resistance must be greater than 1.05 and less than about 1.25 to 1.35).

At 200 yards 76mm is above the upper range for shatter fail and penetrates, beyond 200 yards 76mm falls into the shatter range and fails.

And as you can see, the Rexford crunched numbers for shatter gap fill the bill.

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Improved resistance figures for rounded and chin areas on Panther mantlet:

TAPERED PANTHER MANTLET

Scaling off four Panther mantlet drawings for the rounded areas (2 drawings for chin mantlet, 2 drawings for fully rounded), and averaging the thickness estimates at each angle, results in the following figures by impact angle:

impact angle/thickness/cast deficiency/vertical equivalent resistance (cast deficiency and resistance vs 17 pdr APCBC):

00 degrees/100mm/0.95/100 x 0.95 = 95mm rolled vertical plate vs 17 pdr APCBC (96mm vs 6 pdr)

05 degrees/98mm/0.94/93mm x 0.94 = 93mm (95mm)

10 degrees/97mm/0.94/99mm x 0.94 = 93mm (95mm)

15 degrees/94mm/0.94/98mm x 0.94 = 92mm (94mm)

20 degrees/91mm/0.93/99mm x 0.93 = 92mm (95mm)

25 degrees/88mm/0.93/101mm x 0.93 = 94mm (96mm)

30 degrees/84mm/0.92/103mm x 0.92 = 95mm (100mm)

35 degrees/81mm/0.92/110mm x 0.92 = 101mm (105mm)

40 degrees/78mm/0.91/118mm x 0.91 = 107mm (113mm)

45 degrees/72mm/0.90/124mm x 0.90 = 112mm (118mm)

50 degrees/67mm/0.89/134mm x 0.89 = 119mm (129mm)

55 degrees/63mm/0.89/150mm x 0.89 = 134mm (142mm)

60 degrees/55mm/0.87/156mm x 0.87 = 136mm (151mm)

65 degrees/48mm*/0.86/201mm x 0.86 = 173mm (191mm)

70 degrees/40mm*/0.85/ 251mm x 0.85 = 213mm (248mm)

75 degrees/33mm*/0.84/331mm x 0.84 = 270mm(315mm)

80 degrees/26mm*/0.83/445mm x 0.83 = 369mm (417mm)

85 degrees/16mm*/0.81/597mm x 0.81 = 484mm (396mm)

Notes:

1. *-mantlet edge area aided by underlying armor extension , total combined effective thickness about 55mm

2. Effective resistance against 6 pdr APCBC in brackets

Against 6 pdr APCBC at 30 degrees impact, the estimated effective vertical resistance would equal 84mm x 1.26 slope effect x 0.94 cast deficiency = 100mm of rolled vertical plate.

On the chin mantlet version of Panther G, the lower half mantlet angles from 25 to 85 degrees are represented by flat areas at a 10 degree impact angle. The effective resistances of the chin areas would be:

105mm at 10 degrees = 107mm x 0.95 = 102mm (105mm)

110mm at 10 degrees = 112mm x 0.96 = 108mm (111mm)

319mm at 10 degrees = 334mm x 1.00 = 334mm (334mm)

The drawings on the next page show the relative mantlet areas which would be visible from the front, and this gives an idea of the relative probability of hitting the mantlet at a particular angle. The area within the 0 to 30 degree impact angle range makes up about half of the visible area.

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