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Posted: 9/30/2005 6:38:57 PM EDT
[#1]
It is falling (vertically) at the same speed whether the bullet is fast or slow... but if the bullet is faster, it has reached any particular horizontal distance sooner, therefore it is still higher (has not fallen as far) than if it had reached that same distance at a later time.
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Posted: 9/30/2005 6:40:06 PM EDT
[#2]
It depends on if it's rising or falling.
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Posted: 9/30/2005 6:41:52 PM EDT
[#3]
ibtp (in before the physists) |
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Posted: 9/30/2005 6:44:02 PM EDT
[#4]
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Posted: 9/30/2005 6:45:41 PM EDT
[#5]
Everything falls at the same rate of speed. A .22 bullet and a 16 inch shell will hit the ground at the same time, everything else being equal. |
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Posted: 9/30/2005 6:47:09 PM EDT
[#6]
Here's the valid question....
Fired from a handgun or fired from a rifle? I find handguns with slower bullets often shooting to a higher point of impact than a faster bullet for the same point of aim and same sight zero at closer ranges. Why? Because of the position of the barrel in it's recoil as the bullet exits the barrel. A faster bullet may exit the barrel when it's only elevated a few degrees from horizontal where as a slower bullet is more likely to exit the barrel at a point when the barrel has elevated a few more degrees. As for rifle rounds, faster will generally impact higher at closer ranges. But down range it can get screwed to hell if the faster bullet has a much poorer aerodynamic property than a slower bullet with more slippery shape. I can drive a 40grn Vmax at 3600fps from my accurized AR15 but by 500 yards it's showing a poorer trajectory than something like a 60grn Vmax at 3100fps. |
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Posted: 9/30/2005 6:47:17 PM EDT
[#7]
+1 9.8 m/s^2 |
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Posted: 9/30/2005 6:47:58 PM EDT
[#8]
 A_Free_Man has it correct. |
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Posted: 9/30/2005 6:51:29 PM EDT
[#9]
Thanks. I've got a gun hitting low with the rear sight all the way down. That's with cream puff loads though. I hope when I stoke it on up it will hit a little higher, but not too much higher or I will have to change the front sight. |
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Posted: 9/30/2005 6:55:54 PM EDT
[#10]
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Posted: 9/30/2005 6:56:26 PM EDT
[#11]
It depends on if it's rising or falling.
Bullets don't "rise". They are lofted upward by the bore angle. The bullet is always falling in relation to the C/L of the bore. Here's the valid question.... Fired from a handgun or fired from a rifle? I find handguns with slower bullets often shooting to a higher point of impact than a faster bullet for the same point of aim and same sight zero at closer ranges. Why? Because of the position of the barrel in it's recoil as the bullet exits the barrel. A faster bullet may exit the barrel when it's only elevated a few degrees from horizontal where as a slower bullet is more likely to exit the barrel at a point when the barrel has elevated a few more degrees. As for rifle rounds, faster will generally impact higher at closer ranges. But down range it can get screwed to hell if the faster bullet has a much poorer aerodynamic property than a slower bullet with more slippery shape. I can drive a 40grn Vmax at 3600fps from my accurized AR15 but by 500 yards it's showing a poorer trajectory than something like a 60grn Vmax at 3100fps. Sorry, that was not part of the question. Nothing in there about the barrel moving, handgun, rifle, etc. Uh, you need to read the original post again. The guy said same weight bullet, with different speeds. So how do you speed up a bullet of the same weight? More chamber pressure from a hotter load. What does that do? It causes more recoil. That means the barrel will rise. So we have the same weight bullet travelling faster, through air, from a rising barrel. So how is it going to hit lower? Sorry, again, that is not in the original question. You are introducing another variable. You are changing the angle of the bore. Rusty did not ask this. We have to assume the angle of the bore is the same for slow or fast. |
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Posted: 9/30/2005 7:02:36 PM EDT
[#12]
This is out of a 16" levergun in 357 mag. The loads today were lead bullet 38 Specials with 158 gr bullets. I plan to shoot full house mags with 158 gr jacketed bullets. The rear sight elevator is all the way down and the gun is about 2" low at 50 yards. I want to step the load up to the sights. One click up on the elevator is way too high so I'm "in between clicks" and have to stay at the lowest notch. I will never shoot this gun past 150 yards unless I am just messing around. On meat I won't shoot it past 75 probably. |
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Posted: 9/30/2005 7:04:39 PM EDT
[#13]
Higher, it reaches the target in a smaller time frame and gravity has less time to act upon it. It does not "depend on whether it's rising or falling," if both bullets are fired with the same beginning angle because gravity is acting constantly on the bullets.
Using very simple terminology; Vx1 (velocity of faster bullet, horizontal axis) and Vx2 (velocity of slower bullet, horizontal axis). Vy1(velocity of faster bullet, vertical axis) and Vy2 (velocity of slower bullet, vertical axis), gravity = 9.80m/s^2, and distance to target, 150m. If the "total" velocity of the faster bullet is, say, 150m/s = Vt1 and it is fired at a 5 degree angle the Vy1 component works out to be: sin(5)*Vt1, or sin5*150m/s = ~13m/s with gravity accelerating it negatively (if we consider velocity directed vertically positive) at 9.80m/s^2. Ignoring wind resistance (forgive me) the Vx1 velocity we will consider constant and is given by cos(5)*150m/s = 149m/s, and it will reach the target in about one second and it will not yet have ceased to rise (gravity acting over one second leads to a drop of 9.80m/s in vertical velocity, still have positive velocity left). Now if we halve the total velocity for the second bullet, making it 75m/s (you can, in fact, use the numbers from above velocities and divide by 2), the results are; Vx2=74.7m/s, Vy2 = 6.5m/s. It takes just over two seconds to travel to target, during which it loses 19.6m/s of vertical velocity, it is dropping, in other words. I really hope that was all correct. Edited because I leave extra words in and had the wrong distance to target. |
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Posted: 9/30/2005 7:09:21 PM EDT
[#14]
So, you are using the iron sights... initially zero it at 25 yards. Move back to 100 yds, adjust elevation so your are 2.5" at 100 yds.
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Posted: 9/30/2005 7:11:34 PM EDT
[#15]
The bullet is out of the barrel before any muzzle rise resulting from recoil occurs. I never said it would hit lower. The downward travel starts the moment the bullet leaves the bore. Take two exact setups, rifle and bullet, the only difference being the velocity of the projectile. With the rifles in machine rests, fire them. The faster projectile will impact the target at a higher point than the slower only because it reached the target sooner. Both projectiles will hit the ground at the same time. |
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Posted: 9/30/2005 7:13:04 PM EDT
[#16]
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Posted: 9/30/2005 7:15:12 PM EDT
[#17]
Yes it will be. |
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Posted: 9/30/2005 7:18:43 PM EDT
[#18]
 Rusty asked if they will hit higher or lower.So, either the barrel will rise due to higher recoil and launch the same bullet to a higher trajectory and hit higher. Or, the same bullet will travel faster to the same target because it covered more distance in less time and also hit higher. |
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Posted: 9/30/2005 7:22:37 PM EDT
[#19]
Newp, dat bullet gets out of the barrel way before the effects of recoil take place. |
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Posted: 9/30/2005 7:33:04 PM EDT
[#20]
He seems pretty intent on ignoring reality... |
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Posted: 9/30/2005 7:34:03 PM EDT
[#21]
Why would you have to change your front sight? To lower the point of impact, lower the rear sight. (you will have to drop the muzzle to align the sights, causing the bullet to drop) To raise the point of impact, raise the rear sight (you will have to raise the muzzle to align the sights, causing the bullet to rise) |
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Posted: 9/30/2005 7:36:33 PM EDT
[#22]
[mumbles] ...back seat physicists...[/mumbles]
Let me dust off my cracker jack physics degree. Yep, says BS on it. Guess I'm qualified to give you a load of my own BS then. In every case, the bullet hits high. Regardless of whether you try to factor in recoil, or not. Regardless of where you place the target, or how you site the gun in. Faster bullet will hit high every time. Period. |
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Posted: 9/30/2005 7:38:37 PM EDT
[#23]
Guy I work with changed his front site because he ran out of adjustment in his rear site. It was easier to machine a new front site than mess with the rear. |
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Posted: 9/30/2005 7:44:52 PM EDT
[#24]
Look at the post of his that I quoted again, he is thinking backward.  He didn't run out of adjustment. His rear sight is adjusted all the way down and he is hitting low. All he has to do is adjust the rear sight up to get on target. No sight replacement is necessary. 
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Posted: 9/30/2005 7:55:57 PM EDT
[#25]
This thread just made me sick. This subject is not that complicated.
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Posted: 9/30/2005 8:08:47 PM EDT
[#26]
So your answer would be.....??? |
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Posted: 9/30/2005 8:21:23 PM EDT
[#27]
I think it will hit higher. Recoil will start as soon as the propellant is set off, the bullet doesn't have to leave the barrel. Some of you claim that the bullet will exit before recoil causes the barrel to move. I don't think so: not with a rifle length barrel, not with a .357, and I doubt a levergun has recoil compensation, or a free-floating barrel with special bedding. |
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Posted: 9/30/2005 8:22:46 PM EDT
[#28]
Did anyone read my post? I guess the metric units scared everyone away, sheez.
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Posted: 9/30/2005 8:28:41 PM EDT
[#29]
You are saying the same thing as 90% of the posters.  What did you expect anyone to say? Are you waiting for this? 
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Posted: 9/30/2005 8:48:48 PM EDT
[#30]
Your problem is in red, rear sight moves in the direction you want your impact to go. |
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Posted: 10/1/2005 5:51:12 AM EDT
[#31]
Here's the real problem. The sight elevator doesn't have a notch that will put me right on and the rear sight does not have any other elevation adjustment. The front sight is on the barrel band instead of a dovetail in the barrel so changing it is something I want to avoid. If the full power loads won't zero like I want them to I may have to get a rear sight with better adjustment or cut a dovetail in the barrel and mount a front sight in it. Since this gun is not a long range proposition I want it dead on at 100 yds and maybe a couple inches high at 50 yds. A lot of newer levers have rear sight elavators with only a few positions while older ones had about twice as many postions. |
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Posted: 10/1/2005 6:05:02 AM EDT
[#32]
Are you fucking serious? No one said anything about different bullets, barrels, angles, elevation above sea level, air resistance differences, the position of the moon, or any other horse shit. He said what bullet will hit higher. Only a couple people on here understood the question and some people even thought that bullets are magical and rise against gravity. I suppose if you got a gun to shoot a really fucking fast bullet, like 26000fps, it could resist the earths gravitational pull. Gravity works no matter how fast you go. All things get pulled to the earths surface at the same rate. at the same rate. Do me a favor. take a tube that a bb will fit in, mount it to something stable, and blow a bb out of it with you breath. Now take an air compressor and another bb and use the compressed air to do it. WTF do you think will happen. |
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Posted: 10/1/2005 6:15:52 AM EDT
[#33]
Faster will always hit higher because time in flight is shorter. |
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Posted: 10/1/2005 6:16:27 AM EDT
[#34]
As with any phyiscs problem, you can either do the math assuming "ideal" conditions, or "real world" conditions. Sometimes the change in conditions will change the outcome. Some of the people here were trying to consider every condition, whereas some were assuming "ideal". If you notice, some even said that regardless of the conditions, the change in the only variable (velocity) will have the same relative change in impact. Even with your "really fucking fast bullet".
What are you trying to demonstrate here? |
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Posted: 10/1/2005 6:22:01 AM EDT
[#35]
Don't do anything to your sights until you are shooting the load you want. Once you start shooting that load, see if one of the notches coincides with the zero wou want to acheive. I wouldn't zero a .357 at 100 yards, I would probably choose 50 yards. That should put you about 2.5" low at 100. If you can't zero it because of the lack of notches, either file some new ones or get a new elevator with more notches. |
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Posted: 10/1/2005 6:47:10 AM EDT
[#36]
FFS gentlemen go over to JBM and work the numbers yourself
 same bullet same conditions one at 2,000 FPS MV and the other at 3,000 FPS MV. faster bullets have flatter trajectories that means they're higher at all ranges compared to slower bullets. |
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Posted: 10/1/2005 6:58:54 AM EDT
[#37]
Don't forget it may also hit to the right or left, depeniding on where the barrel was in its oscillation when the bullet departed (barrel twists opposite the rifling, and vibrates from being "stretched" when bullet goes down bore)
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Posted: 10/1/2005 7:38:00 AM EDT
[#38]
And don't forget about sunspots.
They mess everything up. |
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Posted: 10/1/2005 8:00:06 AM EDT
[#39]
Also take into account any swarms of gnats the bullet may pass through. That could ruin EVERYTHING! |
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Posted: 10/1/2005 8:01:31 AM EDT
[#40]
Well for starters, 'every' condition is a bullshit thing. Your trying to tell me that people on this board sat down with pens and pencils and started taking into consideration harmonics, weather, air, heat, gravities other than the most basic version of the earths, barrel movement due to a weak shoulder and set of arms, and all other infinite combinations of infinite variables.... I don't think so... And I am trying to demostrate a simple thought process. An object launched from a barrel with the same initial trajectory will hit in different locations if velocity is the only variable. A bb going at 10fps probably isn't going to go as far or hit as high as one going a few hundred fps. Very simple experiment really. And about my really fast bullet, I was trying to prove that bullets are not 'lighter than air' and the only way a bullet could be is if it was going fast enough to leave the earth for good. |
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Posted: 10/1/2005 8:14:31 AM EDT
[#41]
Remember, Crayola Crowd here. Draw the force vector diagram with the ogive climbing, level, and diving to show the net direction of force on the projectile, don't forget to make appropriate adjustments if projectile is either in or passes the transonic speeds. |
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Posted: 10/1/2005 8:17:39 AM EDT
[#42]
That the faster (compressor powered) BB will strike higher thereby proving The_Reaper' statement a related thread similar in that these two questions are often discussed to death here. |
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