Gun Convergence behavior = buggy???

[Robli]

The point is that nobody is throwing bullets at enemies, so it is totally irrelevant what happens at 21 m/s. 

Speed of a bullet varies between 900 m/s (muzzle velocity) and 90 m/s (terminal velocity). Shape and smoothness of the bullet has some effect on drag, so maybe terminal velocity is not 90 m/s, but is 95 m/s or 88 m/s, but anyway a lot lower than muzzle velocity and a lot higher than the 21 m/s from a football example.

[Livai]

Sorry, but I find the convergence behavior is trash for nose mounted guns. Buggy is even the beautiful version. After some patches nose mounted guns behave a lot different. Before I used 100m as convergence and everything was fine. My aim not changed but some patches messed around and now shooting with nose mounted guns with the same convergence is far far away from that how it was before. Even 500m as convergence for nose mounted guns makes no difference sure I see the all bullets fly more straight through the aimpoint but that was all. Before when you had 500m convergence for nose mounted guns  you could feel that 100m as convergence was a lot better for nose mounted guns. Now all 100,200,300,400,500,550 convergence settings behave the same for nose mounted guns.

 

-> In CloD Blitz tobruk I don't have any problems even more Settings for convergence and when I then switch back to Great Battles I switch back instantly to CloD so much better. Great Battles goes really down hill.

 

 

Edited January 5, 2021 by Livai

[BlitzPig_EL]

Projectiles fired from firearms begin losing velocity as soon as they leave the barrel of the gun.  They NEVER get faster than the speed as measured at the muzzle. NEVER.

I think someone here is very confused about how a projectile fired from a gun is propelled.  They are not internally powered, like a rocket or missile, which could gain speed over time.  They are pushed out of the barrel by a rapidly expanding pressure wave caused by the very rapid burning of the chemical compound (gun powder) that is ignited when the round is fired.  Once the projectile leaves the barrel there is no further acceleration of the projectile.

[unreasonable]

Just now, Livai said:

 

I found a University Powerpoint Präsentation, was about drag, speed, direction change when the wind flows and about deflection. The most interesting part was that a smooth sphere big as a football has a critical speed of approx. 21 m / s where the air resistance decreases again. A bullet is smaller, faster, smooth surface and aerodynamic compared to a football. When a football with a rough surface already above 8 m / s speed has a lower air resistance than in the case of the smooth football but his air resistance increases with increasing Speed slowly but continuously and on the smooth football  approx. 21 m / s  his air resistance decreases with increasing Speed slowly but continuously.

When a football behave this way how a bullet behaves then? = the same way

 

Download Powerpoint Präsentation

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjZjef_0ITuAhUCxIUKHe29AbwQFjAFegQIAhAC&url=https%3A%2F%2Fwww.physik.fu-berlin.de%2Feinrichtungen%2Fag%2Fag-heyne%2Fdocs%2FLNDW2006%2FLNFinal.ppt&usg=AOvVaw2Ct6tLixlfiGM0nWeYc7Yy

 

The graph I think you are referring to on the left in section 3 clearly shows the air resistance for the smooth ball rising at speeds over about 90 kph. The phenomenon of the sudden decrease in drag on a soccer ball is described - in English - here: https://www.grc.nasa.gov/www/k-12/airplane/socdrag.html

 

In short, there is a phase transition in the wake formation, which initially reduces drag. It happens much earlier on a rough ball.  In either case, once it is completed the drag will then continue to increase with higher speed.  Note that this ppt actually has the drag equation in it: section 4. 

 

This phase transition is not relevant for supersonic bullets.   

[LukeFF]

8 hours ago, BlitzPig_EL said:

Projectiles fired from firearms begin losing velocity as soon as they leave the barrel of the gun.  They NEVER get faster than the speed as measured at the muzzle. NEVER.

I think someone here is very confused about how a projectile fired from a gun is propelled.  They are not internally powered, like a rocket or missile, which could gain speed over time.  They are pushed out of the barrel by a rapidly expanding pressure wave caused by the very rapid burning of the chemical compound (gun powder) that is ignited when the round is fired.  Once the projectile leaves the barrel there is no further acceleration of the projectile.

 

Nothing more needs to be said. ??

[356thFS_Melonfish]

11 hours ago, LukeFF said:

 

Nothing more needs to be said. ??

It sort of does because we're in agreement with him we're just not sure why he's saying it?
 

[unreasonable]

Just now, Melonfish said:

It sort of does because we're in agreement with him we're just not sure why he's saying it?
 

 

I am not sure either. He may have been confused by Livai's posts, (easily done), although Livai's only said that drag reduces with higher speed, not that the bullet accelerates (I think English not being his first language ). Which is only true at the wake phase transition, not relevant to bullets.