Smoothbore ball velocity

[Sparkitoff]

There is a debate at the local range regarding the velocity obtained in a smoothbore using a round ball load. I recounted my son's hunt where he took a deer with a .626 ball from a smoothbore and suddenly the crowd split.

I loaded the 1 ounce cup equiv. of FFFg (I think its 80 grains), a cushion wad, ball and overshot card. Its a 28" barrel. I did use a chronograph once and I recall it was 1488 fps average.

One of the guys declared my load could only be "something like 750 feet per second" and "nowhere near fast enough to go through a deer". Half the group then supported his opinion. Some saying since it is a smooth bore it cannot generate enough pressure to obtain "high" velocity.

Those supporting my claim made comparisons to cartridge shotgun ammo - how the shot and equivalent weight slug have nearly the same velocity. They also pointed out the recoil and sound that is very similar to the .54 caliber rifles.

The opposition then said it would take " a lot more powder than that" to get 1400+ fps".

It will be a month before I can get to the range with all the necessary accessories, the smoothbore and the chronograph, but I will see these guys a few times prior to that.

Does anyone have a load for a .62 rifle with approximate velocity and a load for a .62 smoothbore (ball) with approximate velocity? Or any caliber with a similar set of data to compare? Or load data showing velocity for both? Rumor is there is a lunch bet on the table so I will gladly send you a half of a sandwich for your assistance!

 

[Grumpa]

Interesting question! Some quick searching indicates that rifling will actually slow down the projectile in the barrel, and a smoothbore will have the higher muzzle velocity. But, the spinning projectile from the rifle will have the edge in velocity as the projectiles travel further downrange. (Blackpowder behaves differently than smokeless.)

Definitely a question calling for a chronograph.

Richard/Grumpa

 

[Cruzatte]

Didn't Duelist1954 do a video or two on just this very topic? IIRC he was testing out various loads comparing 3Fg and 2Fg powders in a 20 ga. smoothbore.

 

[Rat]

With around 100 grains, I believe a .62 will reach around 1600fps, so I don't see how 1488fps is out of line for the 80 grain charge. I think that I have guesstimated, in the past, using data, that my rifle runs around or at 1600fps with 110 grains. 750fps is certainly a strange guess/estimation. People, in general, don't realize the velocity ML's will produce, or the pressures black powder can generate. A long barrel, small caliber round ball rifle can achieve 2000fps easily I believe.

What kind of sammich is we talking about? Turkey?? Cut in half, or with bite-marks on it?

 

[Crewdawg445]

I'll be honest, interesting subject but I could care less about velocity because my smoothbores big and small have dropped dead everything in Ohio we are legally allowed to hunt! That there tells me velocity and energy are plenty good! Be neat to see some actual numbers, but such things are beyond my little mind!

 

[George]

I loaded the 1 ounce cup equiv. of FFFg (I think its 80 grains), a cushion wad, ball and overshot card. Its a 28" barrel. I did use a chronograph once and I recall it was 1488 fps average.

Some data posted on the forum in the past:

#1
20 bore 38" Colerain smoothbore barrel
.595 ball--319 grains (avg.)
.023 cotton/canvas patch
"moose milk" lube

80 grns. Goex 3F
1419
1381
1375

#2
.600” ball, 1540 fps with 90 gr. 3F and 1400 fps with 80 gr. 3F in a 36” barrel

#3
My own results with .600" ball, 20 ga., 46" barrel, 80 gr. 3F gives a repeated average of 1475 fps.

Spence

 

[Sparkitoff]

Thanks!

 

[Rifleman1776]

I'll be honest, interesting subject but I could care less about velocity because my smoothbores big and small have dropped dead everything in Ohio we are legally allowed to hunt! That there tells me velocity and energy are plenty good! Be neat to see some actual numbers, but such things are beyond my little mind!

Good post, Crew. A lot of folks, maybe all of us, at times tend to get hung up on numbers. A a kid I used to know modern ballistics like some remember baseball statistics. They can be interesting. But, as you point out, meat on the ground is what counts. Ded deer didn't say "that ball wasn't fast enuf". ;-)

 

[tenngun]

Early in my muzzle loading hobby I saw my first Bess, and fell in love. I did ask the same question about velocity and accuracy. The Bess owner asked me a would you rather question. Would you rather be hit with a needle at 1000fps or a bowling ball at a 100.
My..600 on 65 drains 3 f have no trouble exiting deer

 

[Stumpkiller]

Ask your shooting buddies what they think a 12 gauge deer slug moves out at from a breechloading shotgun. With 2-3/4 drams equivalent (75 gr FFg) they are listed at 1,300 fps.

https://www.federalpremium.com/prod...kshot/vitalshok-truball-rifled-slug/pb127-lrs

That's a 1 ounce projectile from a smoothbore. And it's all about the mass, not the shape. That would be 0.660" in round ball diameter to get that weight.

So 80 gr FFg on a slightly lighter 0.626" ball should be 1,400 fps, no problem.

 

[hanshi]

My favorite smoothbore load for my .62 flintlock is a .600" prb over 70 grains of 3F. I settled on this combo due to the great accuracy at 50 yards. I did chronograph it a few years ago and got 1370 fps. 80 grains should give a bit beyond 1400 fps.

 

[Zonie]

In the Lyman's "BLACK POWDER HANDBOOK & LOADING MANUAL", 2nd ed. they show the results of shooting a .690 diameter lead ball patched with a .020 thick patch thru a 26 inch long 12 guage barrel. The barrel was using a #11 percussion cap for ignition.

The results for GOEX 2Fg powder were: 70 gr = 794 fps MV, 80 gr = 881 fps MV, 90 gr = 962 fps MV, 100 gr = 1043 fps MV

The results for Pyrodex RS were: 70 gr = 827 fps MV, 80 gr = 949 fps MV, 90 gr = 1062 fps MV, 100 gr = 1175 fps MV.

A .626 diameter lead ball weighs 368 grains. A .690 diameter lead ball weighs 492 grains.

Just a guess here but as the OP was shooting 3Fg powder, that would bump the velocity from the 2Fg values shown above up into the Pyrodex RS range.
The smaller ball size's lighter weight would bump its velocity up a bit further so if I was going to hold out my thumb and make an semi-educated guess I'd say the velocity of the ball in the original post would be about 1000 fps.

By the way, the sound of a gun when it fires depends a lot on the velocity of the ball/bullet as it leaves the barrel.
A gun shooting at under 1250 fps will make a "BOOM".
A gun shooting at over 1250 fps will make a "CRACK!" because the ball/bullet is traveling faster than the speed of sound.

 

[Rat]

I think spark has a lot of sammiches to send off.

 

[Skychief]

80 grains of 2f under a .595 ball, out of a 42" barrel, is plenty fast for a good buck at 33 yards. Can't help with actual velocity but ya can't argue with the fact I'm basking in the glow of supper a few minutes ago. Deer loin, bell pepper, fresh garlic, a few shrooms, plenty of onion, from a cast iron skillet, served on hearty rye.

Thank goodness it was plenty fast!!!

Best regards and hold my half of the sandwich, I'm full, Skychief.

 

[Skychief]

Interesting question! Some quick searching indicates that rifling will actually slow down the projectile in the barrel, and a smoothbore will have the higher muzzle velocity. But, the spinning projectile from the rifle will have the edge in velocity as the projectiles travel further downrange. (Blackpowder behaves differently than smokeless.)



Definitely a question calling for a chronograph.



Richard/Grumpa

I'd like to learn more about a roundball fired from a rifle keeping its velocity more so than one fired from a smoothbore, all else being equal.

Anybody?

Best regards, Skychief.

 

[shane a gress]

I have filled a lot of tags with my 62 and I don't ever recall not having a pass through with a round ball. One shot was 100 plus yards and went through while busting a rib on the off side.

 

[Rat]

Yes, have shot clear through at 110 yards, paced off three times.

 

[Pukka Bundook]

Shot right through a mule deer with a 20 bore matchlock at 85 yards, using only a wadded and patched .570" ball.
(75 grs 2F)

Skychief,
I too had heard a ball from a smoothbore gets out faster with the same charge.
I am sure it will retain this lead as well, as I can see nothing that would slow it down quicker than from a rifled barrel.
I think what is meant, is the long rage accuracy suffers in the smoothbore, compared to rifle and we can't argue with that.

 

[Skychief]

Pukka, thanks. I understood that a claim was made that a round ball fired from a rifled and smooth barrel at the same muzzle velocity, would find the smoothbore launched ball slowing more so than the other .

I've just re-read the post, and take it as I originally did.

I would still like to understand how that could be.

Best regards, Skychief.

 

[Pukka Bundook]

I understood you well enough Skychief. I was meaning I can't see how that could happen either.
Wandering yes, slowing more, no.