rifled Vs. smoothbore velocity

[whitetrash078]

I recently bought a smoothbore T/C renegade, I noticed in the load data that came with it the velocity is much lower than that of a .54 that is rifled even though the powder charge is the same. The .56 cal ball is only 20 grains heavier than the .54. Why such a difference in velocity between the two?

 

[Wes/Tex]

If the barrels are the same length, I'd put money on the 27/+or- grains of lead. Even that small amount of weight can make a measurable difference.

 

[musketman]

:imo:
Even though the .56 caliber ball is only 20 grains heavier than the .54, the ball has more mass and that means more surface area exposed to drag...

The powder is going to yield the same amount of power per like charges, how much mass that charge pushes on (resistance of the ball's weight) will determine the velocity that is obtained...

The bore of the .56 is also larger than that of the .54's, so the pressure will be different due to this extra volume of space...

Did both examples you quoted use the same powder?

FFFg will give higher pressures than FFg in the same gun...

Barrel length is another factor, giving more time for powder to burn will increase velocity too...

 

[whitetrash078]

I don't know the barrel lengths but the charges are both 100gr of ffg the .56 velocity is 1300 fps and the .54 is 1855fps as quoted by the T/C load manual.

 

[Leonredbeard]

Hey whitetrash,
That seems like an unduly large difference, even with all the factors involved. Your only solution to being sure is to buy or borrow a chronograph and see for yourself. I encourage you to do this and then share the results with us. We always like to know. :hmm: ::
God bless.
volatpluvia

 

[whitetrash078]

I will when I can, but, I am buying my dad a sharps rifle for fathers day and that will pretty much eat up my stash of fun money until I save more. :winking:

 

[Leatherbark]

FWIW.........My T.C New Englander in .54 with its 26 inch barrel will do 1400fps or so with a .530 ball and .015 patch and 80gr of 3fg..............Bob