.58 Muzzle Velocity

[wtilenw]

Anyone have any idea what I may be getting for muzzle velocity out of my .58? It's a Green Mountain 34" bbl 1-70" twist. I'm shooting 100 grains of KIK 2F and a cast pure lead ball .018 patch and Stumpy's Moose Snot. I'm at 4000 ft elevation. I just keep forgetting to take my chronograph to the range with me.
Thanks,
Idaho PRB

 

[Le Grand]

PRB, The old Lyman Blackpowder Handbook shows a .58 caliber rifle with a 32" barrel using 100 grains off GOEX FFg gets 1295 feet per second. That's a percussion rifle, a Zouave in fact which used musket caps. The rate of twist was not given but they did use a .560" ball in a .015"
patch. Then, with the same rifle, a velocity average of 1199 was recorded while using 100 grains of Curtis's & Harvey's FFg powder. The muzzle velocity from your rifle with 100 grains of KIK must be somewhere in that neighborhood. Le Grand

 

[roundball]

Anyone have any idea what I may be getting for muzzle velocity out of my .58? It's a Green Mountain 34" bbl 1-70" twist. I'm shooting 100 grains of KIK 2F and a cast pure lead ball .018 patch and Stumpy's Moose Snot. I'm at 4000 ft elevation. I just keep forgetting to take my chronograph to the range with me.
Thanks,
Idaho PRB

I have the same barrel and haven't chrono'd mine either, but FWIW, TC's load data manual lists their's out of a 28" barrel at 1428 FPS/MV using 100grns Goex 2F.

I wonder if it would be reasonable to speculate that each additional inch of barrel length might generate an additional 25 FPS for a total of another 150 FPS.....1550-1575 FPS ?

 

[rabbit03]

Hello Le Grand can you tell me about my .58 too? I have the same but in 42" and am using 120grns of 2F and idea on the chrono on it? Thanks

rabbit03

 

[rebel727]

I wonder if it would be reasonable to speculate that each additional inch of barrel length might generate an additional 25 FPS for a total of another 150 FPS.....1550-1575 FPS ?

You'll increase velocity for every inch of barrel up to the point where your barrel length exceeds the charges ability to generate pressure. Then velocity will start to fall off.

 

[wtilenw]

Ill take the chronograph next weekend.
Idaho PRB

 

[musketman]

Anyone have any idea what I may be getting for muzzle velocity out of my .58? It's a Green Mountain 34" bbl 1-70" twist. I'm shooting 100 grains of KIK 2F and a cast pure lead ball .018 patch and Stumpy's Moose Snot. I'm at 4000 ft elevation. I just keep forgetting to take my chronograph to the range with me.
Thanks,
Idaho PRB

I have the same barrel and haven't chrono'd mine either, but FWIW, TC's load data manual lists their's out of a 28" barrel at 1428 FPS/MV using 100grns Goex 2F.

Altitude should also come into play for the difference in velocities, Idaho PRB is shooting in Twin Falls, Idaho whereas Roundball is shooting in North Carolina, that a big difference in elevation and air density...

 

[WV_Hillbilly]

I wonder if it would be reasonable to speculate that each additional inch of barrel length might generate an additional 25 FPS for a total of another 150 FPS.....1550-1575 FPS ?

You'll increase velocity for every inch of barrel up to the point where your barrel length exceeds the charges ability to generate pressure. Then velocity will start to fall off.

I think that last bit is supposed to mean that the velocity is NOT less than the velocity of the previous charge weight, BUT that the increase in velocity is not as large as the increase between the previous set of charge weights.

Did I make sense? I hope.
WV_Hillbilly

PS There probably are some rare instances where the velocity actually does drop relative to the previous velocity.

There are too many variables for me to just arbitrarily suggest a velocity figure (or a charge weight for that matter).

I'm thinking that I may open up a new topic on this subject.

 

[Le Grand]

Rabbit03, I'm sorry but that old handbook doesn't show any data from .58 caliber rifles with longer barrel. That percussion with the 32" barrel is the only .58 they used. They do show that gun loaded with the patched round ball and charged with 120 grains of FFg. The velocity shown for that load is 1400 feet per second. Maybe PRB will give us some more up to date information when he remembers to take his chronograph along. Let's hope so, Le Grand

 

[rabbit03]

10-4 I appreciate the reply and will look forward to more posts here that might answer the question for me.

Thanks and happy 4th of July everyone.

rabbit03