How far does a punkin ball fly before it starts to descend?

[golliej]

I am shooting .490 g punkin balls and using 100g of powder in my 50 caliber muzzleloader. I am trying to determine at what point the bullet starts its descent. It shoots a little high at 25 yards, higher at 50 yards and too high at 75 yards. I haven't taken it farther out because I am having trouble with my sights. But I was wondering when I could expect the bullet to start dropping instead of continuing to rise?

 

[paulvallandigham]

Gravity begins to pull on the ball as soon as it leaves the muzzle. It appears to be rising, simply because the sights are set on top of the barrel to make you fire the gun at an angle so that the ball rises to reach line of sight over those sights. If the ball is sighted to hit dead center at 50 yds, it is probably going to rise for a few more yards before beginning to fall. No matter what range you " zero " your sights, that rising to the sights factor is present. When the ball is running out of steam, however, it may be falling by the time it reaches your line of sight, or point of aim(POA) again, Even with modern cartridges, its typical for a rifle sighted in at 100 yds. to have the bullet rise to hit POA at between 25 and 35 yds, and come back down to the same POA at 100 yds. That is one reason we use the shorter distance when testing loads. If a load groups well at 25 yds, and is somewhere near our POA, it will probably be a little high at 50 yds, and be on or just a little low at 100 yds. YOu might want to consult Lyman's Black Powder handbook which has lots of tables and loading data .

 

[omgb]

If you were to drop that ball from a height equal to that o of the muzzle at the time of discharge, assuming th muzzle was level, both balls would hit the ground at the same time. Thus, If you knew the distance to the point of impact of the fired ball, you could divide the time it took the ball to hit the ground (in seconds) into the distance traveled horizontally (in feet) and have the average muzzle velocity of the ball.. Not what you asked of course, but it got me to thinking and this is what came out. Remember, if the muzzle is level, a ball dropped from the muzzle height and a ball discharged from the muzzle with both strike the ground at the same time. Velocity related to the pull of gravity is constant.

 

[Jumpshot]

I will leave the technical explanations to the other guys, heres a simple way to picture it: roll a tennis ball off the edge of your kitchen table. No matter how fast you do it, the ball still starts dropping as soon as it leaves the edge. More speed just makes it go farther before it hits the ground.

All round balls and bullets do the same thing, start to fall as soon as they leave the muzzle. Its the rifles sights that are adjusted to make the barrel 'point up' (relative to the line of sight from your eye to the target) so the projectile 'gets out there a bit' so it can hit the target on the way down. For farther targets, the sights are adjusted make the barrel 'point up' more so the projectile goes further before it hits, or you can leave the sights alone and simply 'hold off' (aim slightly above the target. Has the same effect as adjusting the sights, except holding off involves more guesswork).

This is too small an amount of an angle to notice and it feels like you are pointing the rifle right at the target. But in reality the barrel is at a slight up angle to 'overcompensate' (so to speak) for the drop of the ball or bullet.

When someone talks about a centerifre caliber being a 'flat shooter', all that means is it has a good velocity in relation to the bullet weight (in other words, that bullet is really cookin') so it really 'gets out there' before it falls very far (this would be like the tennis ball rolled off your table fast instead of slow). But it still begins falling as soon as it leaves the muzzle like every other projectile.

Thats my scientifically calculated technical explanation. Not as good as the explanation you will find in a reloading manual, but it gets the basic point across. :grin:

 

[trent/OH]

If your point of impact is getting higher as the range increases, it's possible your barrel is bent upwards ever so slightly. In a well lit area, look along an edge of a flat, and see if it's absolutely straight. It happened to me, and it took a few years of intermitent shooting to discover the problem.

 

[trent/OH]

One more thing. Is your gun a 50 caliber, like we're all assuming, or closer to a 70 caliber? I'm not so certain if you're talking about a .490" punkin ball, or a 490 grain punkin ball. A 100 grain powder charge is stiff for a 50 caliber, but not a heavy load for a 70 or so caliber.

 

[AZ-Robert]

I am shooting .490 g punkin balls and using 100g of powder in my 50 caliber muzzleloader. I am trying to determine at what point the bullet starts its descent. It shoots a little high at 25 yards, higher at 50 yards and too high at 75 yards. I haven't taken it farther out because I am having trouble with my sights. But I was wondering when I could expect the bullet to start dropping instead of continuing to rise?

Yep, as others have said, the ball is rising up to the sight line as it leaves the barrel. That's always the case, but they are usually sighted in so they rise at an angle that has them start back down at around the 60 yard mark. In this case, it sounds like the ball is still on its way up at 75 yards. That may be the result of a bent barrel, a "run out" problem, or the front sight is too low (too short). If it is just a question of a sight that is too short, you can fix that with a new (taller) front sight, or by deepening the notch in your rear sight. If the front sight looks too small, the best bet is to replace it. That is not hard to do... you can get a new one for $5 or less and getting it to fit is a simple matter of filing it down to fit the dovetail cut into your barrel.

As for your question about when you should see the ball reach its peak and begin to descend...

IF you are shooting a .490" diameter lead ball;
IF the ball weighs about 177 grains;
IF you are using 100 grains of GOEX 3F;
IF that gives a MV of about 1757 fps; and
IF your rifle is "zeroed" at 100 yards;

...the ball should reach its peak at about 51 yards and start its descent by about 65 yards.

If your ball is still on its way up at 75 yards, the sights are "zeroed" at some distance beyond 125 yards, or there is something wrong with the barrel.

You might be able to play around with this ballistics calculator to help you figure out what is going on (link below). To use it, you have to crank in your ball's ballistic coefficient. If you are using a round ball of .490" diameter, the BC is .068. You also need the ball's weight, which should be about 177 grains if you are using more or less pure lead. You need the MV your powder load produces... my Lyman's BP manual says 100 grains of 3f GOEX gives about 1757 fps and 100 grains of 2f GOEX gives about 1622 fps if using a .490" round ball. You also need to know how high above the bore your sight line is.... you can use 1" as a default or you can measure it.

Okay, click on the link below, when it opens up the calculator, click on the button that says "Define your own bullet", enter the BC and bullet weight, click the "OK" button, then use your mouse to adjust the red sliders on the right side of the page to set MV and sight line and you will get a graph that shows the ball's flight path.

Dragging the red lines around might let you see what is going on. For example, if your ball is 4" high at 75 yards, move the red range line to the 75 yard mark, then drag the "zero range" slider back and forth until you see 4" in the height of trajectory window... that might give a hint as to what range the rifle is currently zeroed for.

Hope that helped. Here is the calculator:
[url] http://www.norma.cc/htm_files/javapagee.htm[/url]

After you've messed around with that a while, you might want to check out these pages:
[url] http://home.insightbb.com/~bspen/trajectories.html[/url]
[url] http://home.insightbb.com/~bspen/ballistics.html[/url]

 

[Zonie]

If your rifle was set up to zero out at 140 yards, and shooting a .490 roundball over 100 grains of powder, it would be hitting about 3 inches high at 25 yards, 6 1/2 high at 50 yards and 7 3/4 at 75 yards.
At 100 yards it would be 7 inches high. (Note that it is beginning to come down on it's height.)

Of course, I'm only guessing about the 140 yards, but any distance over 130 yards will produce noticable changes like you've seen.

You need to adjust the sights (by filing if necessary) so it's zeroed at about 75 yards.

zonie

 

[golliej]

I showed my ignorance when I said it was a .490 g bullet. I suppose that is the diameter in inches and not the weight? It is a 50 caliber muzzleloader and the gun guy at dicks sporting goods recommended 100 g of powder. Too much?

 

[golliej]

Lots of good information. So should I sight my rifle in to be right on at 60 yards? Do you recommend sabots or round ball for the traditional 50 cal?

 

[paulvallandigham]

Use round ball in a traditonal gun. Make sure they don't sell you one of those guns with a fast rate of twist in the rifling in the barrel. You want a gun with at least a ROT of 1:48, and preferrably 1:60 inches. ( 1 rotation of the ball in 60 inches of barrel) Start with 50 grains and work up by 5 grain increments. when you narrow the range of the good loads for your gun, then you can start changing the charge by 2 grain increments. Most of us are using hunting loads of 75-90 grains of FFg powder. It depends on the length of the barrel on your gun how much powder you can burn effectively. There is no need to try to send that ball out at high velocity. The Lead ball kills because of its initial large diameter and its fast expansion to over 60 caliber on impact, while driving through the deer. At any reasonable range you would shoot an open sighted gun at game, the ball will be driven completely through the deer, broadside.

 

[faw3]

Zonie is stearing ya right, and 100 for a 50 isnt to much, it's like'ly the Max load, (hunting ect) I shoot 110 and 120 out of 2 of my 50's at 100 yd. 60 to 70 is a good start. And a patched round ball. :grin:9 The above post is right also, you'll find different rifles like different things,I go up 10 grs each time and then narrow it down to 5 when Im getting close just to save time) Fred :hatsoff:

 

[Celt]

the gun guy at dicks sporting goods recommended 100 g of powder. Too much?

The gun guy at Dick's sporting goods sells powder too, right? :hmm:

 

[Zonie]

"...Zonie is stearing ya right, ..."
_________________________________________

Now, aside from the time I told the young husband that he should buy his young bride a
"COOKING FOR DUMMIES" cookbook for their first anniversary, when have I told you guys something wrong??

:rotf:
zonie

 

[faw3]

Ya your right what was I thiking... :rotf: Fred :hatsoff:

 

[todg]

When someone talks about a centerifre caliber being a 'flat shooter', all that means is it has a good velocity in relation to the bullet weight (in other words, that bullet is really cookin') so it really 'gets out there' before it falls very far (this would be like the tennis ball rolled off your table fast instead of slow). But it still begins falling as soon as it leaves the muzzle like every other projectile.

Almost right. The bullet weight isn't a factor. It's BC (ballistic coefficient) which works into how fast the projectile decelerates (linear velocity is not constant). Smaller calibers are often 'flatter shooters', but only because it is easier to push smaller bullets at higher velocity with the same amount of powder. The ballistic arc is closer to a line with higher velocity - thus 'flatter'.

 

[RedFeather]

"The guy at Dick's"...........Was at one yesterday, looking at a bolt action .22lr. He starts to hand me a Remington 597 autoloader and tells me it's the same thing. I see a big Winchester Bowie that says "By Gerber" on the tag priced at $25, so ask to see it. Not really by Gerber but, hey, $25 bucks. He says it's no good because they were throwing one at a log IN THE STORE and the blade broke off at the guard. (Not a full tang knife, anyway.) Dick's seems to attract such experts. Mine now only carries .50 Hornady roundballs. Everything else is for inlines.

 

[bnail]

if the muzzle is level, a ball dropped from the muzzle height and a ball discharged from the muzzle with both strike the ground at the same time. Velocity related to the pull of gravity is constant.

Unless the ball is steel. The Earth's magnetism will increase the "rate of fall" for ferous metals due to magnetic attraction, causeing steel to "fall" at a rate of 3.14 times faster than lead . . . it's a fact. :winking:

 

[Jumpshot]

Almost right. The bullet weight isn't a factor. It's BC (ballistic coefficient) which works into how fast the projectile decelerates (linear velocity is not constant). Smaller calibers are often 'flatter shooters', but only because it is easier to push smaller bullets at higher velocity with the same amount of powder. The ballistic arc is closer to a line with higher velocity - thus 'flatter'.

I was just trying to avoid the technical side of things like BC to make the explanation simple. I figured it wouldnt matter because its just an example to illustrate a point, but maybe I oversimplified it too much.

 

[CoyoteJoe]

]Unless the ball is steel. The Earth's magnetism will increase the "rate of fall" for ferous metals due to magnetic attraction, causeing steel to "fall" at a rate of 3.14 times faster than lead . . . it's a fact. :winking: [/quote]
Maybe if you are standing exactly on the magnetic pole. Hope nobody is firing steel shot in Mexico, it would all come whistling right through Colorado. :grin: