Silly Me Post About Tracer Vs Non Tracer.

[stash]

Hmmm....

The part of my brain that stores my limited amount of physics knowledge is fuzzily suggesting that once a projectile leaves the muzzle at a certain velocity, only friction and gravity affect its trajectory.

I could be wrong, but it seems to me that the velocity is a result of its acceleration in the bore, and once it leaves the muzzle it's in free flight, so its decreasing mass would not be an issue affecting trajectory, only its energy state throughout the flight......or.....?????

[nrshida]

You might be right Stash, but then I'm wondering why they can't exactly match the flightpath of tracer and non tracer by increasing propellent in the heavier projectile? Perhaps there is an aerodynamic difference?

[Charge]

I'd say that due to differences in weight (even if aerodynamics were the same) the amount of propellant would only match the arrival time or flight path crossing of projectiles to a certain point, not for the entire flight path. But that is not without problems either.

In case of, say, MG151/20 and different weight projectiles it would be more desirable to match the flight path horizontally to a certain point and not the time of arrival since the time difference is practically negligible, where as if the horizontal flight path difference is great the majority of shots would miss if the tracer would be used as the guideline to direct aim.

Effectively this means that the heavier projectile could leave the barrel with less velocity than the lighter one but still cross a certain point with the lighter one (but at different time), since despite faster speed the lighter round will also decelerate faster due to worse kinetic energy retention. To calculate this point would be pretty wild process but I guess that is why there are tables of flight time and drop to certain distances to aid in combining a sensible belting, and what is more important to calibrate the sight as the propellant loading is what it is and cannot be changed on the field. That would mean that the weapons officer would tell the pilots prior to mission that the tracers can be used to direct fire for, say, up to 300 - 400 meters and that the aiming point is a few degrees above the center of the sight but at 600 meters the majority of rounds will land exactly where the sight is set where as at that distance the tracers may already fall below target, or still fly over it.
In best case the tracers' flight path would cross that of the heavier ones exactly at the desired sight point but there would still be differences at other distances.

If we got to micro level the matter gets even more complicated as the reducing weight will affect the flight characteristics but not necessarily in a positive way, on the other hand the erupting hot gases from burning tracer decreases tail drag etc etc etc....

-C+

[Wiley]

Hmmm....

The part of my brain that stores my limited amount of physics knowledge is fuzzily suggesting that once a projectile leaves the muzzle at a certain velocity, only friction and gravity affect its trajectory.

I could be wrong, but it seems to me that the velocity is a result of its acceleration in the bore, and once it leaves the muzzle it's in free flight, so its decreasing mass would not be an issue affecting trajectory, only its energy state throughout the flight......or.....?????

Reducing mass would have an effect on the bullet's ballistic coefficient, which in simple terms is how rapidly it slows down as it goes downrange.  Two bullets having the same size, shape, and initial muzzle velocity with one of them being lighter and therefore slowing down faster means the one that's slower has more time to fall over the same distance, so it will have a lower impact point.

I don't know anything specific about the tracer/non tracer scenario discussed here, but it wouldn't surprise me if it were true.  In terms of aerial gunnery on vehicle size targets, I'd question how much of an impact it would have on anything other than the briefest of snapshots.

...On a slight tangent, the belts were generally mixed in some fashion, right?  Tracer/API/Incendiary/?  I'd bet there were similar slight ballistic differences between rounds.

Wiley.

[hitech]

Danny told me that tracers in real life have a flatter trajectory because they lose mass in flight.

1st Aces High treats tracers and non tracers the same.

2nd loosing mass in flight would not cause a flatter trajectory.  It would cause the bullet to drop more because less mass would make the bullet slow down more quickly. Hence longer time of flight to target, hence greater drop.

I am not saying that tracers do or do not have a flatter trajectory in real life, only that the causation you stated can not happen.

HiTech

[earl1937]

1st Aces High treats tracers and non tracers the same.

2nd loosing mass in flight would not cause a flatter trajectory.  It would cause the bullet to drop more because less mass would make the bullet slow down more quickly. Hence longer time of flight to target, hence greater drop.

I am not saying that tracers do or do not have a flatter trajectory in real life, only that the causation you stated can not happen.

HiTech

Sir, greatest respect for you and what you have done with this game! <S>...I have a question which I think only you could lay some question in my mind concerning the .50 cal ammo in this game. #1- Have the .50 cal been "de-nuted" as some claim. #2- Is there a chart, or resource where we can see which of the ammo has the most drop and how much each ammo drops, say in 1,000 feet. #3- Salute to Skuzzy for all the help he has been to all of us! <S>

[danny76]

Tracer rounds will always fly slightly higher than ball rounds simply because of their original mass being less than ball rounds, and this mass decreases in flight as the phosphorous burns away.
It is easily visible firing GPMG belts of 1 in 5 tracer, at 6-800yds there is a pronounced variation in the impact zone

[hitech]

Sir, greatest respect for you and what you have done with this game! <S>...I have a question which I think only you could lay some question in my mind concerning the .50 cal ammo in this game. #1- Have the .50 cal been "de-nuted" as some claim.

Of course not.

#2- Is there a chart, or resource where we can see which of the ammo has the most drop and how much each ammo drops, say in 1,000 feet. #3- Salute to Skuzzy for all the help he has been to all of us! <S>

Not that I know of. But you can bring up a target with the .target command at any range you wish, and see the amount of drop at different ranges.

HiTech

[Lusche]

Have the .50 cal been "de-nuted" as some claim.

This is one of the most constant claims in AH almost since the beginning. Especially after each update, you will read a lot like "oh great, HT has now nerfed the 0.50 cal" (or any other favourite piece of equipment).
If only a fraction of that had been true, the .50 would shoot cotton balls by now 

[Karnak]

This is one of the most constant claims in AH almost since the beginning. Especially after each update, you will read a lot like "oh great, HT has now nerfed the 0.50 cal" (or any other favourite piece of equipment).
If only a fraction of that had been true, the .50 would shoot cotton balls by now 

Overwhelmingly those are about the .50 cal.  The only other I've even seen claimed is the German 30mm.

[morfiend]

This is one of the most constant claims in AH almost since the beginning. Especially after each update, you will read a lot like "oh great, HT has now nerfed the 0.50 cal" (or any other favourite piece of equipment).
If only a fraction of that had been true, the .50 would shoot cotton balls by now 

   


  Earl all ordanace in AH is based on LB's,IIRC the 50 cals generate 1.1 pounds of destruction per round.  You can test these things offline or in custom arenas by adjusting the damage required to destroy an object,ya it's over my head to Earl. These days you need to be a computer expert just to play games,not like the old days where a stick,rock or can could make for a great game!!!

  BTW the post that stated the 50 cals were nerfed was about 13 years old back when AH was almost new! the damage model and the way it works has been changed since then this lead some to think HTC nerfed the 50 cals.


  hope that clears thinks up for you abit.



   

[bustr]

Tested 50 cal offline with the target.

P51D
Conv - 300
Alt 1000ft
Level speed 301 ias
Target 300 yards

Tracers on - Concentrated dispersion 5ftx5ft with random dispersion 10ftx10ft at 300 yards.
Tracers off - Concentrated dispersion 5ftx5ft with random dispersion 10ftx10ft at 300 yards.

The IP point was exactly the same relative to the gunsight center and target in both cases with the same 5Mil nose down movement during firing. I suspect that 5Mil nose down depression might have some influence to player complaints. This can be seen with fighters that have wing guns outboard of the main gear with the offline target while shooting on full zoom. "For every action, an opposite and equal reaction".

A case could be made for testing convergence combinations at target 200, 300, 400 to present dispersion clouds as a player aid. The AAF 1945 armorers harmonization manual had graphic illustrations of this for the P51D set to 333yd conv. The assumption for the 50cal and 20mm was an ever expanding 4Mil dispersion cone along the ballistic arc at all ranges out to max effective. The famous "Shotgun Effect".

[Ardy123]

  I think Gyrene is correct if you look at shot out to 1000 yds. I'm willing to bet that the first 300 yds or so there wouldnt be a huge difference in tragectories but once the round are down range at 700 to 1000 yds you would start to see a difference.

  I also have no doubt Gyrene put more than his shhare down range!


   

Although interesting, its prob. irrelevant in that almost all ww2 aerial combat shots were done close in. At least it seems that was what was what pilots were trained to do. Eric Hartman for example, would advise to get in as close as possible, sometimes getting hit by the debris of the planes he was shoot at.  Even in AH, its rare to make shots from more than 400 out, and according to all of you, there wouldn't be much of a diff between 0-~300 or so yards...

[Ardy123]

1st Aces High treats tracers and non tracers the same.

2nd loosing mass in flight would not cause a flatter trajectory.  It would cause the bullet to drop more because less mass would make the bullet slow down more quickly. Hence longer time of flight to target, hence greater drop. Objects of greater mass are more resistant to changes in their state of motion.

I am not saying that tracers do or do not have a flatter trajectory in real life, only that the causation you stated can not happen.

HiTech

This, gravity is a constant force, a falling heavy item accelerates as fast as a falling light item in a vacuum, so the loss of mass causes the round to have less inertia and thus slow down faster.

Is the loss of mass great enough to make a noticeable difference within normal fighting/firing ranges (0-400)?


EDIT: Are the drag coefficients similar for tracer rounds compared to normal rounds?

[Ardy123]

Hmmm....

The part of my brain that stores my limited amount of physics knowledge is fuzzily suggesting that once a projectile leaves the muzzle at a certain velocity, only friction and gravity affect its trajectory.

I could be wrong, but it seems to me that the velocity is a result of its acceleration in the bore, and once it leaves the muzzle it's in free flight, so its decreasing mass would not be an issue affecting trajectory, only its energy state throughout the flight......or.....?????

Baring every shot has perfectly identical mass & shape. Also both rounds would have to have had perfectly equal amounts of force generated by the charge... All of which is not the case in RL. I wonder if the heat generated from the first shot would ever so slightly alter the shape of the barrel and/or alter the combustible characteristics of the charge.