Did the US test the 88/L71?

[C.G.Erickson]

Is it 88 rounds or 88mm rounds?

What else would they be testing? 88 rounds of what?

[C.G.Erickson]

After a while w/o TN access - some notes:

C.G. - tests I posted are not "scientific" - because part of testing I have quoted is not - they were meant to be the stuff that goes to manual like "Avoid engaging T-54 tank with 88mm PaK from the front". There is second part that states all scientific datas like impact velocity and such, but I don't have it and neither does my source.

And as a someone who posted this, taking time to collect it and translate it I am a bit insulted by you stating it is "worthless". Sure, it may not be stuff that you can draw a lot of conclusions about guns or tank armor but those are real world results of testing guns vs armor.

While I had no intent of insulting your research and hard work. As a whole the test conclusions confirm my interpretation of the Yugo tests.

 

If this was a "Field Test" then the "Scientific" part of this test probably doesn't exsist.

 

Good stuff for wargamers.

[C.G.Erickson]

Funny that you still think range cards useful against moving targets. Such a practice would contribute to a tanker's dream, overrunning arty in a pinch.

What you also consider debunked remains in play. The German experience looms large because it is they who had the hard choices

to make, as for some reason the allies did not so employ 90mm and 3.7in as AT guns, except in extremis. The Germans found that they had to make

conversions that rendered the guns useless as AAA. Ever wonder why? I did.

 

A flat trajectory does not rule out the need for elevation changes. Again, you presume a flat battlefield, which remains seldom the case. Look outside your window, it might suggest to what I refer. Shifting targets rapidly will require elevation changes, unless your enemy cooperates via single file. Maybe you

have just not done direct fire over 500m? Waiting for the tanks to close that distance makes for poor life expectancy. A Red Army antitank study I have shows

4 AT lost per tank destroyed in such combat. Not every battle was fought in the bocage, so the statistical averages do not apply well if you happen to be E. or S of Caen, N, S, W of Paris, in Provence or Champagne and so forth. The E. front and W. desert had their own special norms, as you recognize.

 

Ken

 

The studies I have done is that at the end of the war 88's were used mainly as Arty in the ground role. Not so much as they were that good, but the German Army did not produce enough ammo for their regular arty pieces. In reference, compare the number of 88's firing compared to the usual German Arty on the Seelow Heights.

 

Whether the Germans wished the 88 as a "Dual Purpose" gun or not. It was a splendid weapon capable of both the AA and HE Direct/Indirect mode of fire. The Artillery graduated site installed on it allowed it to be fired in the ARTY/AT role without range cards. This type of sight can be found also on the Stug series of vehicles.

 

The missing factor is how well the gun crews were trained in both the AA and Ground fire missions. 88's were more often than not under direct Luftwaffe control and required extreme measures to turn them against ground targets. This in itself supports your theory that the 88 was not a "Dual Purpose" gun, but when turned to ground targets was excellent in its results as such. So in my opinion, without a "trained" gunner the 88 was average in the AT role, but with a well practised gunner an 88 was deadly in the "ground Support role." Dual Purpose? With the right gunner, yes. Without....NO.

 

Cheers

[Ken Estes]

Cary, At the end of the war, the Allies are in the III Reich proper, encountering the tens of thousands of 88mm available from AA duty. Any AA gun has the instrumentation in its FC to provide indirect fire. The AA mode 88 had primitive sighting that would allow direct fire as well, just not easily manipulated vs multiple moving tanks. By the time the Red Army assaults the Seelow Heights, we are in March45, and arty ammo and guns must have been ever scarcer. AA was likely pressed into service anywhere.

 

Just rec'd an e-mail from Jim Corum, who just published his bio of W. vRichthofen last year:

 

I know that the 88 (the early 1930s version that was used in Spain) was used to take out fixed positions-- first used by Von Richthofen as a means to break Basque defenses in 1937. but I did not see references to the 88 use as an AT gun. It is possible-- I know that it was used as such in 1940.

[jwduquette1]

Wasn't there an article or series of articles written for Armor Magazine on tank and antitank combat in the Spanish Civil War. This was a number of years back. Its been awhile since I read these so take this with a large measure of salt, but wasn't there some mention in one of the articles of the 88's use in an antitank role?

 

sorry -- just a quick add -- but Zaloga had also written an article on tank combat or antitank combat in the Spanish Civil War. But I don't recall where this was published.

Edited April 28, 2009 by jwduquette1

[C.G.Erickson]

Cary, At the end of the war, the Allies are in the III Reich proper, encountering the tens of thousands of 88mm available from AA duty. Any AA gun has the instrumentation in its FC to provide indirect fire. The AA mode 88 had primitive sighting that would allow direct fire as well, just not easily manipulated vs multiple moving tanks. By the time the Red Army assaults the Seelow Heights, we are in March45, and arty ammo and guns must have been ever scarcer. AA was likely pressed into service anywhere.

 

Just rec'd an e-mail from Jim Corum, who just published his bio of W. vRichthofen last year:

Ken

 

Examined a "slap on" sight for an 88. Was not primitive in any respect as far as zeroing. Range dials for Elevation and Azimuth. Direct sight even had a "super elevation" adjusting crank to ensure zeroing at battle ranges. Much like the artillery sights from the Stug 3. Deadly accurate in the hands of artillery gunners.

 

What I did notice was differences in sight mounts between the Flak 36 and Flak 37. Flak 36 sight was emplaced by 4 set screws set equidistant around a vertical circle. Once you set the sight for battle range charts to match the bore sight, you had to remove the sight by leaving either the upper or lower sight screws tight while loosening the opposite screws to remove the direct fire sight. Any loosening of the "fixed screws would throw off the zeroing setting of the sight. Complicated and failure prone.

 

Flak 37 had sight "pinned" in place by upper and lower machined dowels which correctly lined up the Direct Fire Sight each and every time it was removed for AA fire and then re mounted for Ground fire applications.This practically eliminated "zeroing problems" for removeable sights. Making the 88 a much more viable Dual Purpose Gun.

 

C.G.

[Mobius]

Prz

 

I should have made myself clearer in the T-33 post. That 3000 + muzzle velocity was for projectile integrity testing.

 

Compare it to the 88 projectiles for 3000 + velocities vs targets.

8" @ 0:Two complete penetrations with projectile passing through plate. 3124mv and 3257 mv. Two ABL penetrations. All Projectiles Intact. 3001 mv 3038 mv.

 

6 1/16" @ 30:Two complete penetrations, projectile through plate. All Projectiles intact 3008 mv 2971 mv

 

5 1/8" @45: One complete penetration, projectile through plate. Projectile fractured. One projectile shattered. 3288 mv 3211 mv

 

3 7/16" @ 55: Two complete penetrations. both projectiles fractured. Projectile fragments passing through plate. One partial penetration projectile fractured. 3334 mv on two penetrations. 3310 mv on 21/2 deep partial.

 

Yes, when is the book coming out?

This info would be good to disseminate in permanent, quotable form and not just on a forum post that will someday be pruned.

[alejandro_]

German projectile tested was APCBC

US 90 mm rounds were 90mm M82, 90mm M77, and 90mmT33

 

Did the US ever test APCR PzGr-40/43? that would have made the tests even more interesting.

[scotsman]

Funny that you still think range cards useful against moving targets. Such a practice would contribute to a tanker's dream, overrunning arty in a pinch.

What you also consider debunked remains in play. The German experience looms large because it is they who had the hard choices

to make, as for some reason the allies did not so employ 90mm and 3.7in as AT guns, except in extremis. The Germans found that they had to make

conversions that rendered the guns useless as AAA. Ever wonder why? I did.

 

A flat trajectory does not rule out the need for elevation changes. Again, you presume a flat battlefield, which remains seldom the case. Look outside your window, it might suggest to what I refer. Shifting targets rapidly will require elevation changes, unless your enemy cooperates via single file. Maybe you

have just not done direct fire over 500m? Waiting for the tanks to close that distance makes for poor life expectancy. A Red Army antitank study I have shows

4 AT lost per tank destroyed in such combat. Not every battle was fought in the bocage, so the statistical averages do not apply well if you happen to be E. or S of Caen, N, S, W of Paris, in Provence or Champagne and so forth. The E. front and W. desert had their own special norms, as you recognize.

 

Range cards are useful against moving targets...again at least at the average engagement ranges that represent western europe. You can not take the german experience (born out of numeric inferiority more than anything else) and the russian experience and equate that to what the western allies dealt with. They didnt employ the US 90mm and British 3.7" more in that role simply because they didnt have to. Once western industrial superiority was translated into numeric superiority of all types at the front, there simply wasnt a need to force guns into that role...especially after the advent of APDS for the 6pdr etc. Nor did they fire at the same sort of average engagement ranges...

 

I am not presuming a flat battlefield at all -- and I am perfectly willing to defend the stand I am taking based on data not opinion. Look up the TETAM study Ken...it gives you the average length of in line-of-sight and out-of-line-of-sight segment lengths by range for all of Germany (to name but one example). All you have to do is compare the speed made good of the AFV to the segment length and you will know what the exposure time is. Couple that with good terrain analysis on the part of the gunner, and you should get a pretty effective coverage of the defended area, even without automation tools. Depression and super-elevation was part of the data collection...

 

As for german conversion to the pure AT role...optional...not mandatory....the 3.7" didnt convert and retained capability as did the 90mm ... and there is no reason the germans could not have chosen the same equipment model. Once again their numerical inferiority backed them into a no-choice corner where it was damned if you do and damned if you don't.

 

I have done plenty of DF on the majority of the german ranges - US, British, and German...and again I disagree with your premise. If you did it for real you --know-- what battlesight zero is in relation to your GDP or defensive position. Are you telling me you didn't use doctrinal engagement methods? I did...from 105mm down to the MG's...

 

As for the statistics of ATG gun survival...its easy to get lost in the noise. How many are killed by artillery prepartory fires, how many by DF tank engagement, how many by infantry close combat, and on the list goes. Every bit of terrain is different so its hard to generalize...

 

Finally a simple examination of the ballistics involved will tell you at these MV and ranges there is not much in the way of round drop to worry about. Most of the WW2 ATG I interviewed (3.7" included, all allied) generally speaking, simply worried about hitting the target at average engagement ranges. They only did aim spot targeting when the battlefield coniditions allowed them to...more typically it was serve and fire center of mass as fast as you could, applying shots to specific target areas when the target was very close...

Edited April 30, 2009 by scotsman

[scotsman]

It doesn't make either DP, it makes them, just "good enough" in a pinch. Dual Purpose implies two very different roles for a system, neither of which the system excels, but which can be used equally effective in both roles. The 5"/38 was just that. It wasn't the best system for AA work, nor the best for ground/sea targeting. It was the best compromise given limited deck space and the need for both roles on one ship.

 

Again...being an ex grunt...this seems to be to be quibbling over words...if you use it in the role it just is...regardless of whether it was designed for it or not...walks like a duck, quakes like a duck, its a duck...

 

ATGM are 'dual purpose' weapons today....many a gunner around will tell you how alternative tgts (machine gun positions/snipers) were killed with AT missiles. Are they classified as DP weapons? No....not officially....but I don't care about monikers and titles as a grunt....all I care about is killing him before he kills me... A 10lb HEAT weahead on a TOW is fine for the task, even though it was never designed for it...

 

We use it in the role and its DP....the rest is semantics again... and the moniker doesn't necessarily have effectiveness tied to it either. 25pdr was DP in my sense of the definition as well. Was it an optimized AT gun? No - but it was so used....and not necessarily in the manner in which the original designers intended either...

 

Walks like a duck, quacks like a duck, its a duck....

 

You guys want tight definitions of DP...and I'm perfectly ok with a loose definition as defined by user experience...

Edited April 30, 2009 by scotsman

[Ken Estes]

Range cards are useful against moving targets...again at least at the average engagement ranges that represent western europe. You can not take the german experience (born out of numeric inferiority more than anything else) and the russian experience and equate that to what the western allies dealt with. They didnt employ the US 90mm and British 3.7" more in that role simply because they didnt have to. Once western industrial superiority was translated into numeric superiority of all types at the front, there simply wasnt a need to force guns into that role...especially after the advent of APDS for the 6pdr etc. Nor did they fire at the same sort of average engagement ranges...

 

I am not presuming a flat battlefield at all -- and I am perfectly willing to defend the stand I am taking based on data not opinion. Look up the TETAM study Ken...it gives you the average length of in line-of-sight and out-of-line-of-sight segment lengths by range for all of Germany (to name but one example). All you have to do is compare the speed made good of the AFV to the segment length and you will know what the exposure time is. Couple that with good terrain analysis on the part of the gunner, and you should get a pretty effective coverage of the defended area, even without automation tools. Depression and super-elevation was part of the data collection...

 

As for german conversion to the pure AT role...optional...not mandatory....the 3.7" didnt convert and retained capability as did the 90mm ... and there is no reason the germans could not have chosen the same equipment model. Once again their numerical inferiority backed them into a no-choice corner where it was damned if you do and damned if you don't.

 

I have done plenty of DF on the majority of the german ranges - US, British, and German...and again I disagree with your premise. If you did it for real you --know-- what battlesight zero is in relation to your GDP or defensive position. Are you telling me you didn't use doctrinal engagement methods? I did...from 105mm down to the MG's...

 

As for the statistics of ATG gun survival...its easy to get lost in the noise. How many are killed by artillery prepartory fires, how many by DF tank engagement, how many by infantry close combat, and on the list goes. Every bit of terrain is different so its hard to generalize...

 

Finally a simple examination of the ballistics involved will tell you at these MV and ranges there is not much in the way of round drop to worry about. Most of the WW2 ATG I interviewed (3.7" included, all allied) generally speaking, simply worried about hitting the target at average engagement ranges. They only did aim spot targeting when the battlefield coniditions allowed them to...more typically it was serve and fire center of mass as fast as you could, applying shots to specific target areas when the target was very close...

All very nicely put, but, you know, firing ranges in Germany and the US are relatively flat and easy. Fighting from terrain hastily occupied or from the march may not conform to one's favorite setup. We will leave your definition as DP=fire can be put on two or more kinds of target. This makes almost any weapon dual purpose, mind you, rifles to rockets.

 

We do range cards in tanks as well, but would never fire on a tank target with them, unless in fog or somehow unable to have visual, and then only if it would not reveal own position while firing 'blind.'

 

The reason that the US and UK did not make other arrangements/mods for their AAA for AT use is that they were not so employed as a matter of course. I already pointed out the exigencies for them that provided the motivations. Allied forces rarely operated at such a short string after 1941.

 

I would never count on engaging opposing tanks at 600m as a routine. over 1200m a first round hit cannot be guaranteed for most of these guns. I have seen plenty of multiple kilometer LOS landscapes in W. Europe.

 

You are most certainly counting upon a mostly flat world.

[C.G.Erickson]

All very nicely put, but, you know, firing ranges in Germany and the US are relatively flat and easy. Fighting from terrain hastily occupied or from the march may not conform to one's favorite setup. We will leave your definition as DP=fire can be put on two or more kinds of target. This makes almost any weapon dual purpose, mind you, rifles to rockets.

 

We do range cards in tanks as well, but would never fire on a tank target with them, unless in fog or somehow unable to have visual, and then only if it would not reveal own position while firing 'blind.'

 

The reason that the US and UK did not make other arrangements/mods for their AAA for AT use is that they were not so employed as a matter of course. I already pointed out the exigencies for them that provided the motivations. Allied forces rarely operated at such a short string after 1941.

 

I would never count on engaging opposing tanks at 600m as a routine. over 1200m a first round hit cannot be guaranteed for most of these guns. I have seen plenty of multiple kilometer LOS landscapes in W. Europe.

 

You are most certainly counting upon a mostly flat world.

Ken

 

Was there a set of rules covering differences in elevation shooting? Like the rules for cant of a tank? Like add one, left one....etc?

 

C.G.

[Ken Estes]

Ken

 

Was there a set of rules covering differences in elevation shooting? Like the rules for cant of a tank? Like add one, left one....etc?

 

C.G.

Surely there were, but I do not recall them, or even worrying about it, since BOT engagement would cover the difference. My remarks on

the fallicy of the flat battlefield are because some people think the dual gunner/pointer not a problem, because one never had to change

elevation once range was set. As targets appear, they are themselves at different elevations on the land, relative to gun position; in the

offensive, the constant changes of position and slope of the ground make elevation control as critical as deflection.

 

Curiously, the 120mm fcs in the M103 heavy tank had a cant corrector, likely because it was intended for those "very infrequent" long

range engagements. I wonder if the same gun in the original AAA mount had it for its "DP" role?

[Ken Estes]

Look up the TETAM study Ken...it gives you the average length of in line-of-sight and out-of-line-of-sight segment lengths by range for all of Germany (to name but one example). All you have to do is compare the speed made good of the AFV to the segment length and you will know what the exposure time is.

This one strikes me as truly wierd. Does anybody thing Germany of today bears much resemblance or has the same topography vs. Germany of 1944-45? Urban sprawl, anybody? In any case, Germany was the location for only a short period of WWII for ground fighting, and there was little call for Allied AT guns, let alone AAA pressed into such service.

 

As for german conversion to the pure AT role...optional...not mandatory

Rommel's harried AA cdr in No Africa apparently differed in his opinion. Of course, by 1943, there were lots of dedicated 88mm AT guns entering service, perhaps reducing the imperative overall. We really do not know how many guns were modified from what you consider DP mountings.

[C.G.Erickson]

I was wondering about point blank range when it comes to 3.7 at range between 500 to 800 meters.

 

Muzzle Velocity 2600. Exactly how much does it drop at that range. According to my ballistic tables(For rifle bullets) for best Ballistically Efficient projectile, at 500 meters my 30-06 drops 69 inches with a velocity of 2900. So if the 3.7 acts in the same way, then at 500 meters it should drop somewhere between 72 to 80 inches.

 

So if a gunner places his reticle on Center of mass and pulls the trigger, he will miss "short". Point and shoot without regards to elevation attention will mean firing too low. This is if his sight is perfectly bore sighted. Did 3.7 crews zero their detachable Direct Fire Sight before shooting? A 500 meter zeroe would be the best under the relative short ranges of Northwest Europe.

 

Can anyone elaborate about Sight zeroing for the 3.7? This would make a great deal of difference in snap shot accuracy. Also would determine the efficiency in transferring the gun between AA to AT role.

 

C.G.

[Mobius]

I was wondering about point blank range when it comes to 3.7 at range between 500 to 800 meters.

 

Muzzle Velocity 2600. Exactly how much does it drop at that range. According to my ballistic tables(For rifle bullets) for best Ballistically Efficient projectile, at 500 meters my 30-06 drops 69 inches with a velocity of 2900. So if the 3.7 acts in the same way, then at 500 meters it should drop somewhere between 72 to 80 inches.

Do we know the velocity at 500m? I could find the drag factor if I knew that. Then run it through my program.

What I have now shows only a 1.78 foot rise over 500m.

Edited May 2, 2009 by Mobius

[GregShaw]

I was wondering about point blank range when it comes to 3.7 at range between 500 to 800 meters.

 

Muzzle Velocity 2600. Exactly how much does it drop at that range. According to my ballistic tables(For rifle bullets) for best Ballistically Efficient projectile, at 500 meters my 30-06 drops 69 inches with a velocity of 2900. So if the 3.7 acts in the same way, then at 500 meters it should drop somewhere between 72 to 80 inches.

 

So if a gunner places his reticle on Center of mass and pulls the trigger, he will miss "short". Point and shoot without regards to elevation attention will mean firing too low. This is if his sight is perfectly bore sighted. Did 3.7 crews zero their detachable Direct Fire Sight before shooting? A 500 meter zeroe would be the best under the relative short ranges of Northwest Europe.

 

Can anyone elaborate about Sight zeroing for the 3.7? This would make a great deal of difference in snap shot accuracy. Also would determine the efficiency in transferring the gun between AA to AT role.

 

C.G.

Sporting bullet BC isn't going to be much use for calculating the trajectory of a 3.7in shell. The 3.7in shell will have a BC of well over 1.0. Most of the sporting bullet drag tables are based off of the G1 tables. The G1 tables use a 1 inch (25.4mm), 1 lb (454 gram) flat base projectile 3 inches long with a 2crh point for the 1.0 reference. The 3.7in will have somewhere around 7x that sectional density and probably a much finer crh point. I can't even find a ballistics calculator that will handle a 180000 gr 3.7 in projectile with a BC better than 2.0, but a 3.7in certainly won't have a 6ft drop and 200 m/s velocity loss over 500 meters.

 

Greg Shaw

[Ken Estes]

So the 3.7 inch round defies gravity? Anybody have an M105D telescope reticule pic handy??

 

Well, vive la France!

 

 

Gorka provided me this manual on the AMX-30 (1977), and the reticles would be for its 105mm, HE [OE] and HEAT [OP].

 

As one can see, there is an appreciable drop at even 500m, especially for the HE, which I presume has a MV of c.2800 fps.

 

Can't go against Mother Nature can we?

Edited May 2, 2009 by Ken Estes

[JWB]

If the MV of that gun is 2600 f/s (788m/s) and loses no velocity then the projectile drop will be equal to time squared multiplied by g/2. So 500m/788m/s equals .6346s. .6346s squared equals .402as^2. .402^2 times g (9.82m/s/s)/2 =1.977m projectile drop. All of that assumes the barrel is perfectly perpendicular to the line of gravity. It also assumes the projectile is pointing directly straight ahead with no tilt upwards or downwards due to various secondary rotational effects.

[Ken Estes]

Exactly, many tanks Mr. Newton...I mean Jimmy!

[Shortround6]

A very, very rough and ready formula for figuring point blank range is MV + 10% = point blank range. ALL projectiles will fall 16 ft in the first second of flight. Gun is aimed so that projectile never rises more than 4-5 feet above line of sight at close range and max point blank range is when projectile falls 4-5 feet below line of sight, depending on size of tank target. ALL projectiles will fall 48 feet in the second second of flight. It is in this just over point blank range area that high velocity guns really show to advantage. An 800m/s gun not only has 330 metres more "BP" range than a 500ms feild gun but at 900-1000meters is only slightly into it's second second of flight as apposed to the end of the 2 seconds for the feild gun. This may mean a drop of 25 ft or so for the 800m/s gun vrs 64 feet of drop for the 500m/s gun.

 

Any gunner with any smarts should have figured this into their point blank setting. Although they might shave a bit on the close range hight. Don't want to shoot over if they get close;) although if the tanks get to 3-400meters the 3.7 guns are in a bit of trouble;)

[GregShaw]

So the 3.7 inch round defies gravity?

That's not what I said. I said a BC calculator for small arms isn't going to be very accurate for a 3.7in projectile. The most flexible trajectory calculator I could find shows a 15,000 gr 2in projectile with a BC of 2.0 and 2600 fps MV being down about 55 inches at 500 yard, with no vertical offset for the sight, and with a remaining velocity of 2380 fps. Given my calcs are at 500 yds rather than 500m that's probably pretty close to JWB's figure for 500m. Thats about 6 inches flatter than a 30.06 155 gr Palma Matchking at 2800 fps at 500 yards, and 130+ inches flatter at 1000 yds. And even that is for a 2.15 lb or so 2in projectile vice a 25lb+ 3.7in one, so still nowhere near the SD of the 3.7in.

 

Greg Shaw

[C.G.Erickson]

Any gunner with any smarts should have figured this into their point blank setting. Although they might shave a bit on the close range hight. Don't want to shoot over if they get close;) although if the tanks get to 3-400meters the 3.7 guns are in a bit of trouble;)

 

Was the Direct Fire sight on the 3.7 a fixed reticle or graduated moving reticle(Like 2lber) for range adjustments? The wire ring sight(also found on 6lber) was for extreme close in work when non focusing magnified sight got blurry at close range.

 

How about including all the other AA guns used in a dual purpose capacity? German 37 and 20, and my fav, the US quad .50 mount.

 

C.G.

[C.G.Erickson]

That's not what I said. I said a BC calculator for small arms isn't going to be very accurate for a 3.7in projectile. The most flexible trajectory calculator I could find shows a 15,000 gr 2in projectile with a BC of 2.0 and 2600 fps MV being down about 55 inches at 500 yard, with no vertical offset for the sight, and with a remaining velocity of 2380 fps. Given my calcs are at 500 yds rather than 500m that's probably pretty close to JWB's figure for 500m. Thats about 6 inches flatter than a 30.06 155 gr Palma Matchking at 2800 fps at 500 yards, and 130+ inches flatter at 1000 yds. And even that is for a 2.15 lb or so 2in projectile vice a 25lb+ 3.7in one, so still nowhere near the SD of the 3.7in.

 

Greg Shaw

Huh?

 

Using a guesstimate off of my shooting tables for rifle bullets I calculated 72 to 80 inch drop. Uhhhh....JWB calculates it at 1.977 meters drop....isn't this larger than 72 inches?This was predicated upon physics, gravity works. I could have used round nose projectiles instead of best Ballistic Coefficient. Drop would have been much more prevalent.

 

Mixing in yards vs meters is not even a consideration.

 

I shoot competively....I have to know EXACTLY what the drop is for given range.

[Mobius]

Tle lowest angle my program goes is .001 degrees. At that I have the shell dropping 7.1' or about 85".