How to explain bullet arc............ at the bar.

[Turbulent Turtle]

Well, if you turn it sideways, the barrel will not be pointed up so the bullet will start falling as soon as it exits the barrel. It's really not rocket surgery.

 

[savagedasher]

Well, if you turn it sideways, the barrel will not be pointed up so the bullet will start falling as soon as it exits the barrel. It's really not rocket surgery.

You did stay at the Holliday Inn. Smiles Larry

 

[Turbulent Turtle]

I sure did, the one in De Forest, WI.

 

[xr650rRider]

If they are using a ballistic calculator, change the zero distance, to the distance to the target. When your turning turrets, that's what your doing, changing zero to target distance. So for 1000 yd target with 1000 yd zero, they can look at table and see max path that occurs slightly past 500 yds. For normal calculation with say 100 yard zero, the drop calculated for 1000 yds is the point you would have to aim at above the target, if you didn't turn your turrets.

 

[johnfred1965]

Really guys, aint it s squared x square root of 3 divided by 4 when north of equator but south of the continental divide?

South of the Continental Divide? Which continent are you shooting on?

 

[mr45man]

The only arc that a bullet has is from gravity. A bullet starts to fall toward the ground from the instant it leaves the barrel.

For all practical purposes this is it in a nut shell.

 

[Johnny_V]

The only arc that a bullet has is from gravity. A bullet starts to fall toward the ground from the instant it leaves the barrel.
A good example of this is to roll a ball off the end of a table. That is what a bullet does too. Another example is water coming out of the end of a garden hose.
The only reason you see a bullet rise in the charts is because the barrel is pointed up at an angle.
Bullets do not rise when they leave the muzzle. If that were true then one could shoot around corners by simply turning the gun sideways.
Wolfdawg

I agree totally. To simplify Wolfdawg's explanation, set up a rifle, level the barrel to zero, and fire a round. The instant the bullet exits the muzzle, gravity becomes its enemy. Turn the barrel sideways or upside down so long as the barrel is kept level, gravity will have its way. Although I would love to see one of those "around the corner" shots.

 

[MagnumManiac]

Please correct me if my terminology is incorrect, but, isn't the arc of a bullet described as elliptical, it's not a true concave arc, it changes as the distance gets further and the drop increases at a faster rate.
This is how I always thought of it.

Cheers.

 

[BoydAllen]

Getting back to the original question, tell your buddies to set their programs so that they are sighted in 12" high at 100 yards, and have their target distance at 600 yards. Set their interval for whatever they like, say 25 yards. From that they should get a table that shows the height of their bullets impacts, for target distances every 25 yards from 25 yards to 600. Here is something that is close. I used the Berger manual for the velocity from the 7mm SAUM with a 180 grain bullet, and the BC of the match hybrid of that caliber and weight. The formatting was lost for the table but if you look carefully in the drop chart, you will see that the first column is the distance to target, and the second is height of bullet impact above target center at that distance, I jiggled the numbers to come close to your example, but it is not perfect. Any of their software should be able to produce something similar. (I would think.) This is from the JBM calculator.

Trajectory
Input Data
Ballistic Coefficient: 0.674 G1 Caliber: 0.284 in
Bullet Weight: 180.0 gr


Muzzle Velocity: 2800.0 ft/s Distance to Chronograph: 10.0 ft

Sight Height: 2.20 in Sight Offset: 0.00 in
Zero Height: 12.20 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg

Wind Speed: 10.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg
Target Height: 12.0 in


Temperature: 70.0 °F Pressure: 29.92 in Hg
Humidity: 0 % Altitude: 1000.0 ft

Vital Zone Radius: 5.0 in


Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Column 1 Units: 1.00 in Column 2 Units: 0.20 MOA
Round Output to Whole Numbers: No

Output Data
Elevation: 15.929 MOA Windage: 0.000 MOA

Atmospheric Density: 0.07222 lb/ft³ Speed of Sound: 1128.2 ft/s

Maximum PBR: 360 yd Maximum PBR Zero: 306 yd
Range of Maximum Height: 171 yd Energy at Maximum PBR: 2206.5 ft•lbs

Sectional Density: 0.319 lb/in²

Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (clicks) (in) (clicks) (ft/s) (none) (ft•lbs) (s) (in) (clicks)
0 -2.2 *** 0.0 *** 2804.4 2.486 3142.9 0.000 0.0 ***
25 1.8 35.0 0.0 0.5 2771.3 2.456 3069.1 0.027 4.7 90.4
50 5.6 53.3 0.1 1.1 2738.4 2.427 2996.7 0.054 9.5 91.0
75 9.0 57.5 0.3 1.6 2705.8 2.398 2925.7 0.082 14.4 91.5
100 12.2 58.3 0.5 2.2 2673.4 2.370 2856.1 0.110 19.3 92.1
125 15.1 57.5 0.7 2.7 2641.2 2.341 2787.8 0.138 24.3 92.6
150 17.6 56.0 1.0 3.3 2609.3 2.313 2720.8 0.166 29.3 93.2
175 19.8 54.1 1.4 3.9 2577.6 2.285 2655.0 0.195 34.4 93.8
200 21.7 51.9 1.9 4.5 2546.1 2.257 2590.6 0.225 39.5 94.4
225 23.3 49.4 2.4 5.0 2514.8 2.229 2527.3 0.254 44.7 94.9
250 24.5 46.8 3.0 5.6 2483.8 2.202 2465.3 0.284 50.0 95.5
275 25.4 44.1 3.6 6.2 2453.0 2.174 2404.5 0.315 55.4 96.1
300 25.9 41.2 4.3 6.8 2422.4 2.147 2344.9 0.345 60.8 96.7
325 26.0 38.3 5.1 7.5 2392.0 2.120 2286.4 0.377 66.3 97.4
350 25.8 35.2 5.9 8.1 2361.8 2.093 2229.0 0.408 71.8 98.0
375 25.2 32.0 6.8 8.7 2331.8 2.067 2172.8 0.440 77.4 98.6
400 24.1 28.8 7.8 9.3 2302.0 2.040 2117.7 0.472 83.1 99.2
425 22.7 25.5 8.9 10.0 2272.5 2.014 2063.6 0.505 88.9 99.9
450 20.8 22.1 10.0 10.6 2243.1 1.988 2010.7 0.538 94.8 100.5
475 18.6 18.6 11.3 11.3 2214.0 1.962 1958.8 0.572 100.7 101.2
500 15.8 15.1 12.5 12.0 2185.0 1.937 1907.9 0.606 106.7 101.9
525 12.6 11.5 13.9 12.7 2156.3 1.911 1858.1 0.641 112.8 102.6
550 9.0 7.8 15.4 13.3 2127.8 1.886 1809.3 0.676 118.9 103.2
575 4.8 4.0 16.9 14.0 2099.5 1.861 1761.5 0.711 125.2 103.9
600 0.2 0.2 18.5 14.8 2071.4 1.836 1714.7 0.747 131.5 104.6
15-Nov-16 00:33, JBM/jbmtraj-5.1.cgi

 

[B Nettesheim]

In relation to your friends backgrounds, compare a bullets arc to the shape of a nice tit looked at from the side.
A c cup might compare nicely to a 600 yard trajectory.
A d size might be more like a 1000 yard trajectory.

 

[Joe Salt]

My thoughts Exactly!

Joe Salt

 

[PDS]

And of course with some of those "enhanced" gals you might think of the trajectory of an 81mm mortar.

 

[Mozella]

And of course with some of those "enhanced" gals you might think of the trajectory of an 81mm mortar.

Until they get older, and then it's more like the arc when Pee Wee Herman throws a shot put.

 

[SG4247]

It is really simple:

Explain the initial angle that the cannon bore, wrist rocket, gun barrel, or spit wad straw is set at - with respect to the horizon determines the shape of the trajectory. Straight up vertical, vs 45 degrees, vs zero or level to the horizon - should be easy to correlate to old Road runner cartoons.

Then, the only factors (vectors) involved after the spit wad leaves the straw is: spit wad weight and velocity at that initial angle from the horizon, gravity force acting straight down vertical on the spit wad, and drag force acting against the nose of the spit wad in the horizontal.

Those two vectors noted above gravity and drag (which have force and direction) act against the inital angle, mass and speed of the spitwad - determining where it eventually lands.

Should be easy to demonstrate spit wad B.C. at the bar....

 

[SheepDog]

The bullet rises away from the ground to get to the line of sight but that bullet always falls from the bore axis line as long as the bore axis line is >-90 and <90 to a perpendicular to the gravitational pull.

 

[Jammer Six]

45 years ago, in the heat of puberty, I thought I might want to attend church. So I went a handful of times.

One of the sermons I heard started off "if you see a man in a bar hit his wife...", and I immediately rushed home, found dad, and asked him what he would do. He listened politely, then he looked puzzled, and said "it wouldn't happen to me. I don't go into bars."

I said "okay, but dad, just say you were in a bar and..." and he said "no, I wouldn't be in a bar. I have no use for bars. I don't go into bars."

It was a frustrating conversation for me.

It took me twenty years, but then I started to understand what he was saying, and I think of it now every time I hear something that includes "we were in a bar and..."

How do you explain bullet arc at the bar?

Well...

 

[Fast14riot]

If someone doesn't understand that the height of leg A (drop or come-up) on a right triangle can't be the same length without crossing C (hypotenuse aka direction bore is pointed) at half way of leg B (aka line of sight), then I'm not sure discussing exterior ballistics in the bar is going to work out. Meaning, bullets do not rise above the line of the bore.

I believe it was Mythbusters who fired a gun horizontally and dropped a bullet at the same time, guess what, they hit the ground at the same time.

 

[SheepDog]

"How do you explain bullet arc at the bar?"

Well, you start off asking, "do you think that free discrete quarks can exist in nature or do they combine and recombine so fast that they transmute into other particles and can't exist as free discrete particles?"
If their eyes glaze over or or stumble into "all men are free" or "we don't allow quarks in here - theres a bar for them over on.." then there is no reason to try to explain a parabolic trajectory in words of two syllables or less.

 

[Jammer Six]

Now that was funny.

 

[SheepDog]

Now that was funny.

Thank you!