Skychief
69 Cal.
What's the muzzle velocity of a .310 spit-patched roundball, shot with 20 grains Scheutzen 3f, out of a 40" barreled flinter? :idunno:
Thank you, Skychief.
Thank you, Skychief.
FPS with this load???
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Durned if'n I know.
The closest information I have is the Lyman BLACK POWDER HANDBOOK & LOADING MANUAL , 2nd ed. which gives velocities for a .310 diameter roundball shot from a 26", 1:66 twist barrel using GOEX 3Fg powder.
Unfortunately, 30 grains of powder is the minimum load shown and it is most likely from a percussion barrel.
In that case, 30 grains of powder gave a average velocity of 1940 fps.
I once ran a linear regression calculation on the data and arrived at a muzzle velocity of 1874 fps for a 25 grain, 3Fg powder load.
That's just a mathematical estimate so don't hold me to it.
One things for certain though.
The .31 diameter roundball only weighs about 45 grains so it doesn't take a lot of powder to get it moving fast.
The closest information I have is the Lyman BLACK POWDER HANDBOOK & LOADING MANUAL , 2nd ed. which gives velocities for a .310 diameter roundball shot from a 26", 1:66 twist barrel using GOEX 3Fg powder.
Unfortunately, 30 grains of powder is the minimum load shown and it is most likely from a percussion barrel.
In that case, 30 grains of powder gave a average velocity of 1940 fps.
I once ran a linear regression calculation on the data and arrived at a muzzle velocity of 1874 fps for a 25 grain, 3Fg powder load.
That's just a mathematical estimate so don't hold me to it.
One things for certain though.
The .31 diameter roundball only weighs about 45 grains so it doesn't take a lot of powder to get it moving fast.
I can give you some info which might help you get in the ballpark, but it's with a .30.
The barrel is 38" with a 1:56" twist rate, I shot .295" balls weighing 39.4 grains, in a .008 patch using Wonder Lube. With 15 gr. Goex 3F the average of 5 shots was 1611 fps, SD 35. Using 25 gr. Goex 3F, average was 2120 fps, SD 43.
I have used the 25 grain velocity in a ballistics calculator to figure the drop at 100 yards, and when fired on real targets it proved to be exactly on the prediction, so I have high confidence that velocity is correct.
Spence
The barrel is 38" with a 1:56" twist rate, I shot .295" balls weighing 39.4 grains, in a .008 patch using Wonder Lube. With 15 gr. Goex 3F the average of 5 shots was 1611 fps, SD 35. Using 25 gr. Goex 3F, average was 2120 fps, SD 43.
I have used the 25 grain velocity in a ballistics calculator to figure the drop at 100 yards, and when fired on real targets it proved to be exactly on the prediction, so I have high confidence that velocity is correct.
Spence
zimmerstutzen
70 Cal.
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Just remember that muzzle velocity for such a light weight ball is lost rapidly after about 30 yds. Probably close to a 70% or 75% loss at 100 yds ie a muzzle velocity of 2000 fps would drop to about 500 or 600 at 100 yds.
Other than just curiosity, why do you need to know that?
And, FWIW, that tiny ball will slow down so rapidly that a given mv at 25 yards will be considerably slower.
And, FWIW, that tiny ball will slow down so rapidly that a given mv at 25 yards will be considerably slower.
Curiosity is all the reason needed.Rifleman1776 said:
With the velocity and one drop figure at any spot along the trajectory, we know the velocity and drop at every spot. Mathematics and physics are powerful stuff.
Small balls do slow down quicker than large ones, but not so much as many people think. That's part of the education a chronograph can give us.
Here are the numbers for my .30 caliber rifle shooting a little .295" ball, for velocity and drop out to 100 yards.
Mv = 2120 fps
25 yd. = 1675 fps = 0 drop
50 yd. = 1315 fps = .4” low
75 yd. = 1076 fps = 2” low
100 yd. = 947 fps = 5.5” low
Tested in the field, these figures are bang on.
Spence
Col. Batguano
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I wonder what the maximum velocity you can actually (safely of course due to pressure considerations) get with a 30 or 32 cal RB actually is? :hmm:
Can't argue with your tests. But those results are surprising.
zimmerstutzen
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You actually fired over two chronos at the same time? One at muzzle and the other at the target distance. How much deviation was there in shot strings?
5.5 drop at 100 is next to nothing compared to wind drift.
And I miss spoke when I said a 70% loss in velocity. it is a 70% loss in energy (ft lbs) from muzzle to 100 yds.
Muzzle loading to the point that you have exact drop at various distances, is not particularly helpful unless you are using laboratory loading
5.5 drop at 100 is next to nothing compared to wind drift.
And I miss spoke when I said a 70% loss in velocity. it is a 70% loss in energy (ft lbs) from muzzle to 100 yds.
Muzzle loading to the point that you have exact drop at various distances, is not particularly helpful unless you are using laboratory loading
hanshi
Cannon
Wild guess; 1400fps to 1500fps.
Looks like your information gives me a chance to check out the free roundball ballistics calculator I downloaded years ago. :grin:
Your data:
Mv = 2120 fps
25 yd. = 1675 fps = 0 drop
50 yd. = 1315 fps = .4” low
75 yd. = 1076 fps = 2” low
100 yd. = 947 fps = 5.5” low
The programs answers:
Mv = 2120 fps
25 yd. = 1571 fps = 0 drop
50 yd. = 1179 fps = 0.1" low
75 yd. = 996 fps = 2.4" low
100 yd. = 876 fps = 7.5" low
Not too bad. I think I'll keep it.
Your data:
Mv = 2120 fps
25 yd. = 1675 fps = 0 drop
50 yd. = 1315 fps = .4” low
75 yd. = 1076 fps = 2” low
100 yd. = 947 fps = 5.5” low
The programs answers:
Mv = 2120 fps
25 yd. = 1571 fps = 0 drop
50 yd. = 1179 fps = 0.1" low
75 yd. = 996 fps = 2.4" low
100 yd. = 876 fps = 7.5" low
Not too bad. I think I'll keep it.
I use the Hornady calculator, it's free, and it agrees to a high degree with a good proprietary program I used for years.Zonie said:Not too bad. I think I'll keep it.
http://www.hornady.com/ballistics-resource/ballistics-calculator
Spence
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Skychief
69 Cal.
Rifleman1776 said:
I'm planning a trip to hunt Kodiak Bear in Alaska.
I didn't know if I should break down and buy a can of pepper spray for backup.
:haha:
Just be sure to get the Kodiak sized can.
It's kinda expensive but it comes with its own set of 8" wheels. They help a lot when your pulling that 85 pound pepper spray bottle up the hills.
:grin:
It's kinda expensive but it comes with its own set of 8" wheels. They help a lot when your pulling that 85 pound pepper spray bottle up the hills.
:grin:
Billnpatti
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If you don't have a chronograph or access to one, you can use any of the estimated MVs that have been posted and it will get you in the ball park. Close enough for most any estimation of the trajectory or kinetic energy at any given distance. Select whatever MV you think is the most accurate, and plug it into this calculator and it will give you all the data for your ball at any reasonable distance. Go all the way to the bottom where it says "NEW" and click on that.
http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/rbballistics.html
http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/rbballistics.html
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Billnpatti
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That kind of reminds me of an old story.
A hiker was going hiking in Alaska and he asked an old hunting guide how to tell if there are bears in an area. "Well, son, you look for bear droppings."
"What do bear droppings look like" asked the hiker.
"Well, bears eat many things but you will find the remains of small animals and fruit seeds in their droppings. But watch out for grizzlies"
"What should I do to avoid running into one of them?"
"Some folks will wear little bells on their clothing to let the bears know that they are coming. They will also carry bear spray."
"How will I know if grizzlies are in the area?"
"Same as for any other bear, look for their droppings."
"What do grizzlie droppings look like?"
"They smell like bear spray and have little bells in them." :rotf: :rotf: :rotf:
A hiker was going hiking in Alaska and he asked an old hunting guide how to tell if there are bears in an area. "Well, son, you look for bear droppings."
"What do bear droppings look like" asked the hiker.
"Well, bears eat many things but you will find the remains of small animals and fruit seeds in their droppings. But watch out for grizzlies"
"What should I do to avoid running into one of them?"
"Some folks will wear little bells on their clothing to let the bears know that they are coming. They will also carry bear spray."
"How will I know if grizzlies are in the area?"
"Same as for any other bear, look for their droppings."
"What do grizzlie droppings look like?"
"They smell like bear spray and have little bells in them." :rotf: :rotf: :rotf:
zimmerstutzen
70 Cal.
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Using one chronograph at one distance doesn't give velocity at both muzzle and the distance down range. It relies on supposition and assumptions. Ie you did not really measure the muzzle velocity and distance velocity at the same shot.
With a 30 caliber a grain or two difference or one patch slightly were than the next makes a huge difference. Ie the need for laboratory precision for VALID results. Not hard to follow.
With a 30 caliber a grain or two difference or one patch slightly were than the next makes a huge difference. Ie the need for laboratory precision for VALID results. Not hard to follow.
