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Optimum Round Ball Caliber

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im very interested in what is ment by, thin, was it lands? is that how deep they are or how wide? those guns were and are tack drivers. want to learn something here. may be my block writing is bad but if you dont understand the content, well 40 to 70 thousand under stand the content at a couple of other places. get calls every week that they like what i have in content. the only complaints i have got on sidelocks ive built is they are too pretty to shoot and shoot they do indeed. i dont dress up to play i dress up for real.
 
Being a student of exterior ballistics I have many times studied the tables in the Lyman handbook. As one can see, all prb's have increasing B.C's, but velocity plays a factor in the equation.
Ex: the .350 RB, with a BC of .049 can be SAFELY propelled to approximately 2500 fps, which gives it 142.38 inches of drop at 300 yards.
The .562 RB, BC of .079, can be safely shot at 1800 fps, with a drop of 137 inches drop at 300 yards.

Not much difference, huh?

But a HUGE difference in energy; the 36 arrives at 300 yards with a whopping 35 ft/lbs of energy, and the 58 arrives carrying the mail with 239 ft/lbs.

The paper target wouldn't notice the difference, but the animal/critter/redcoat, what-have-you definitely would.

Both the 50 and 54 cal have a drop at 300 around 110 inches, and remaining energies of 173 and 223 ft/lbs, respectively, nothing to sneeze at.

The flattest shooting projectile Lyman tested was the 454613 45 cal Minie, with a BC of 156 and velocity of 1800 fps. It dropped 84 inches at 300 yards and had 518 ft/lbs energy left. I've often wondered if that hollow based minie pushed to that velocity would have ANY accuracy.

So....the Optimum Round Ball would GREATLY depend on WHAT you intended to do with it, IMHO.
 
"Where in Billy-Blue-Blazes did George Washington get a sheet of typing paper to shoot at?"

I wondered where he got a typewriter to use it in.
 
I could live with a .45 for everything and take game up to approaching 100 yds. I've never had a failure with a .45 prb. If I intended on doing a good bit of shooting at 100 yards or a little over, I'd choose the .50. Both calibers have taken deer at those distances.
 
I like a .40 because it’s easy on the wallet, easy on the shoulder, not too hard on a squirrel or bunny, yet is less finicky to load than smaller cals, can take a 3/8” rammer, bucks wind better than smaller cals, has enough energy when loaded hot for close range medium game like small woods deers, and doesn’t foul out as fast as a .32 or .36.

Might not whoop or wholerp ‘em as much as a .58 but considering all I hunt are small game and 99% of my shooting is simply at sheets of paper or tin cans, no real reason to use a 300 grain piece of lead and 70 or more grains of powder every time I trip the trigger.
 
Wait a minute, if you fired a .40", .45", .50", .52", .56", .58", and .62" ball at the same velocity, would they not have the same trajectory? What if you dropped them all off the Space Needle at the same time, would they not hit the ground at the same time? Doesn't trajectory depend on velocity, if the projectiles are identical? Or have the same B.C.?
 
By the way, .62" is the perfect, I mean best, caliber. :)
 
LD,
I'm sure it did address .40 too.

It did? :D

I'm having a little tongue-in-cheek fun with you with my question.... since as far as trajectory goes, when talking "flat" vs "bowed" you're talking purely fight time and surface area friction... and a .390 ball is going to be faster = flatter than a .50 and way flatter than a .54, out to 50 yards, when using the same powder loads. ;)

GOEX shows the .40 at 1960 fps with 65 grains of powder, the .50 at 1550 fps with 70 grains of powder, and the .54 at 1400 fps with 70 grains of powder.


LD
 
It did? :D

I'm having a little tongue-in-cheek fun with you with my question.... since as far as trajectory goes, when talking "flat" vs "bowed" you're talking purely fight time and surface area friction... and a .390 ball is going to be faster = flatter than a .50 and way flatter than a .54, out to 50 yards, when using the same powder loads. ;)

GOEX shows the .40 at 1960 fps with 65 grains of powder, the .50 at 1550 fps with 70 grains of powder, and the .54 at 1400 fps with 70 grains of powder.


LD
Tongue in cheek would explain a lot, as I'm not understanding making comparisons at different velocities. ??
 
OK you wrote "optimum" round ball caliber..., but you didn't really define your parameters, just "flattest trajectories". Well..., IF we use very similar powder loads and all the bullets are spheres, the flattest trajectory is from the fastest projectile. Because the longer amount of time that gravity can act upon the projectile, the more it drops. I knew the .40 would be faster than the .50, .52, or .54 which is why I asked if the book covered .40 caliber. ;)

LD
 
But about the sweet spot being somewhere between .50 and .54, the ballistic coefficient of lead round ball goes up with spherical volume but at the same time the resistance to acceleration applied across the surface area of the bore also increases. So at some point those two lines cross and there the sweet spot is.

Huh?:confused:
 
It's a math thing. Plot the two curves and the sweet spot is where they intersect.
It was an interesting exercise with pen and paper and the tables included in Lymans BP Manual.
 
if you fired a .40", .45", .50", .52", .56", .58", and .62" ball at the same velocity, would they not have the same trajectory? But they do not have the same ballistic coefficient. They have different sectional densities. The ballistic sectional density is different from sectional density as used in physics. In physics sectional density is the mass divided by the cross-sectional area and has units of mass/dimension squared. In ballistics, sectional density is weight in pounds divided by diameter in inches squared. They differ by a factor of Pi if resolved to common units. Volume and mass/weight of a round ball is a function of diameter cubed. Cross-sectional area is a function of diameter squared. Ballistic sectional density is a function of diameter. Ballistic coefficient is section density divided by form coefficient. Form coefficient for a sphere is independent of size. The Lyman BP Handbook has BC's for a variety of calibres. Those BC's correspond directly to (ballistic) sectional density divided by a coefficient of form of 1.52 for round balls.
All else being equal, the higher the sectional density, the less the loss of speed in flight, the less the loss of energy in flight, and the less the drop in trajectory. A ballistics trajectory calculation shows that for equal initial velocities, smaller calibre round balls will have greater drop than larger calibre round balls when measured at the same distance.
 
It's a math thing. Plot the two curves and the sweet spot is where they intersect.
It was an interesting exercise with pen and paper and the tables included in Lymans BP Manual.

Try it with real powder patch and ball. :D
 
It's a math thing. Plot the two curves and the sweet spot is where they intersect.
It was an interesting exercise with pen and paper and the tables included in Lymans BP Manual.
How about the target thing at the range? Need gun, powder, lead and target. Find that very interesting. If math thing is important maybe bring a chronograph and then will have real numbers. Have always considered the Lyman data an approximation or a starting point. Look at differences recorded with different powders.
 
Yeah, any table of results is what happened then with their stuff, not today with your stuff.
And then there's other factors in there as well. For instance, as the ratio of weight versus cross sectional area goes up you have to kick the balls' behind with more and more energy to get a given velocity. There's kind of a trade off when going bigger in diameter in as much as they don't slow down as fast just as they don't speed up as fast. And then decreasing the diameter reverses the effect. This is all just something that caught my attention once upon a time.
The .52's I have weren't designed around that math but were made for paper patching off the shelf fifty caliber cartridge rifle molds and sizing down to .519 but I'm gonna check out how the .515 round ball works. No way they'll ever shoot ball as flat and straight as the 43" long barrel Dixie po' boy fifty though!
:thumbs up:
 
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