PRB drop estimate

[J-Bar]

Consider a patched round ball, solid lead .530 diameter ( for a nominal .54 caliber muzzleloader) weighing let’s say 220 grains, launched at 1500 FPS from a barrel that is absolutely level.

Approximately how far below the bore line will the ball drop at 50, 75 and 100 yards?

I’m not very good at using online ballistic calculators apparently. Thanks for your help.

 

[arcticap]

I am not going to run a ballistics program.
However, a .54 PRB launched at 1700 FPS and sighted in to be dead on at 50 yards is calculated to drop -4.2 inches at 100 yards.
See post #2 about loading a 90 grain powder charge and how to sight it in to be dead on at ~75 yards and -3 inches low at 100 yards:--->>> https://www.huntingnet.com/forum/black-powder/144488-54-cal-drop.html

 

[J-Bar]

I am not going to run a ballistics program.
However, a .54 PRB launched at 1700 FPS and sighted in to be dead on at 50 yards is calculated to drop -4.2 inches at 100 yards.
See post #2 about loading a 90 grain powder charge and how to sight it in to be dead on at ~75 yards and -3 inches low at 100 yards:--->>> https://www.huntingnet.com/forum/black-powder/144488-54-cal-drop.html

Thanks for the link.

 

[rodwha]

Consider a patched round ball, solid lead .530 diameter ( for a nominal .54 caliber muzzleloader) weighing let’s say 220 grains, launched at 1500 FPS from a barrel that is absolutely level.

Approximately how far below the bore line will the ball drop at 50, 75 and 100 yards?

I’m not very good at using online ballistic calculators apparently. Thanks for your help.

By the barrel being absolutely level are you in essence asking about it being zeroed at 0 yds to where the ball immediately begins to drop?

I have an easy to use ballistics calculator app (free) called Bullet Drop.

 

[rodwha]

A .530” lead ball should weigh 224 grns, right? Is this an alloy? The BC should be 0.073.

My calculator didn’t like me using 0 for sight in or for sight height so I used 1 yard for the zero and 0.001” sight height. Close enough. I also use 900’ elevation for myself.

At 25 yds it has dropped 0.5”, at 50 it has dropped 2.3”, at 75 it has dropped 5.7”, at 100 yds it has dropped 11”, and at 125 yds it has dropped 18.7”.

 

[J-Bar]

Thank you.

 

[paul harm]

From Lymans first edition BP handbook [ which for me is much, much better than their second edition ]
535 RB, 1500 fps, drop in inches,
25yds -.52
50yds -2.32
75yds -5.77
100yds -11.29
125yds -19.23
150yds -30.03
A 11 inches at a 100yds may sound like a lot, but they also give mid-range heights.
50yds .64"
100yds 3.33"
125yds 5.81"
150yds 9.24"
So if you were to sight it in at 100yds it would only be about 3" high at mid range which isn't all that bad for deer hunting. That's just about point blank shooting, not having to worry about rise or drop. At 150 you better be pretty good at judging distances and using " Kentucky windage ".
Lymans 1st edition gives data for velocities from 1000 to 2200, distances from 25yds to 300, energy, drop, mid-range, bullet path, time of flight, wind deflection for 5, 10, 20, and 30mph for every velocity and distance listed above. Tables are from a .319 to a .565RB and bullets. Loads for revolvers and shotguns are also shown. It's a 240 page handbook and if you can find a used one don't pass it up.

 

[J-Bar]

Thank you.

 

[RecoilRob]

This is kind of a trick question....being he stated that 'the barrel is absolutely level' which completely throws off all ballistic calculators with zero's at various distances which means they all incorporate a bore angled above the line of sight to hit a point at some distance. Time of flight of the bullet from a level barrel will be the same as if dropped from that same height....which will be roughly .5 seconds for most people in a standing position.

So with the velocity being shed rapidly by the round ball...it obviously can't go more than maybe 150 yds before striking the ground which I'm assuming means a drop of about 5 feet in that distance and might travel even less depending on local conditions.

 

[J-Bar]

This is kind of a trick question....

No trick intended. The variables of sight heighth and range at which the rifle may be zeroed were eliminated by specifying a level bore. I was only interested in gravity’s effect on the round ball at a muzzle velocity of 1500 FPS, and the previous posts answered my question satisfactorily.

 

[paul harm]

I once shot the silhouette match at the NMLRA. The farthest target was a bear at 200 yards with other targets at 50, 100, 150, and 175. I used a 54 flintlock and loaded 90grs for everything up to 100 yards and then went to 120grs. { the barrel maker, Bill Large , recommended the heavier load ]. According to Lymans 90grs of 3F should give 1546fps and 120grs 1826fps. We shot off hand except the bear and that was anyway you wanted - prone for me. Got lucky that day, tied for high gun [ 14/20 ] and won a L&R lock.

 

[Jackrabbit1957]

You have my admiration Paul, shooting silhouette with a rocklock takes some serious practice and knowing your rifle! Kudos sir.

 

[Loyalist Dave]

Of course..., you'll need to verify that at the range from the bench. Barrel length will alter muzzle velocity. It's one thing to launch that .530 ball from a 28" TC Hawken, and another from a 38" Colerain barrel, and quite another from a 42" barrel. If the books have one MV and you're using a shorter barrel, you may come up with a lower velocity, and with a longer barrel, you might get a higher MV. You may also need to compare 2Fg and 3Fg loads with your length barrel. I've been taught that in .54 when you use more than 3 drams (80 grains) in a 38" or longer barrel and a 1:56 or slower twist, you really should go to 2Fg to get the most increase for your load. (No idea if round bottom rifling vs. square bottom rifling makes a difference or not.)

LD

 

[alsaqr]

Consider a patched round ball, solid lead .530 diameter ( for a nominal .54 caliber muzzleloader) weighing let’s say 220 grains, launched at 1500 FPS from a barrel that is absolutely level.

Use the round ball calculator:

http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/web_apps/rb_ballistics.html

 

[J-Bar]

Thank you.