Muzzle Velocity

Muzzleloading Forum

Help Support Muzzleloading Forum:

Cpt Flint

40 Cal
Joined
Feb 18, 2020
Messages
345
Reaction score
403
Does anyone know what the muzzle velocity of a .40 caliber PRB is with 60 grains of 3FG
from a 42” barrel?
 
Joined
Jan 27, 2008
Messages
22,552
Reaction score
20,112
Location
Republic mo
Lyman shows it as 1936
All will depend on multi conditions
60 grains by volume of pyrodex is a little faster then GO.
Swiss is also hotter
An old of powder such as elephant or Diamond back will be a little slower, Flint slower then percussion, hot caps make a difference. Ball patch combo, dirty gun, hot day, cold day, lube, all make a difference.
I have never owned a chrono, but I have read folks often don’t get the results that testers get.
1850 may be more your area
 

Rock Home Isle

58 Cal.
Joined
Feb 13, 2021
Messages
2,003
Reaction score
3,112
Location
Johnstown Colorado
I was shooting my TVM Natchez PoorBoy just last week. .490 RB and 40 grains of fffg, I hold dead on out to 125 yrds. I was shocked when I figured this out. I love that little .40 calibre. It has really become a fun accurate gun to shoot
 
Joined
Jan 27, 2008
Messages
22,552
Reaction score
20,112
Location
Republic mo
But one should look to down range performance. I don’t have info down range for a .40, but a .45 at 1900 fps at the muzzle slows to 1380 at fifty yards
At 1700 fps it’s 1230
A .36 at 1900 slows to 1260 at fifty yards while at 1700 its 1120. Not much of a difference. Go for your most accurate load. Ball is a poor projectile and velocity loss is major.
 
Joined
Feb 28, 2005
Messages
6,679
Reaction score
1,852
Location
Colorado
Does anyone know what the muzzle velocity of a .40 caliber PRB is with 60 grains of 3FG
from a 42” barrel?
I've done quite a bit of chrono checking and none of it with 40 caliber. But, I learned enough to be able to say with a high degree of certainty that if you could gather together 20 shooters all with 40 caliber guns with 42 inch barrels and have them all shoot ten shots over the same chronograph with 60 grains of 3f you would find that there is no definitive answer to the question.

It would be very enlightening though and would probably indicate a velocity range with very few extreme outlier results. 😀
 
Joined
Jan 27, 2008
Messages
22,552
Reaction score
20,112
Location
Republic mo
I've done quite a bit of chrono checking and none of it with 40 caliber. But, I learned enough to be able to say with a high degree of certainty that if you could gather together 20 shooters all with 40 caliber guns with 42 inch barrels and have them all shoot ten shots over the same chronograph with 60 grains of 3f you would find that there is no definitive answer to the question.

It would be very enlightening though and would probably indicate a velocity range with very few extreme outlier results. 😀
That would be more realistic. There would be a range of numbers and most would follow close.
I think it was black powder tV that tried shooting with commercial wads vs tow in a smoothie. He got almost two hundred feet per second just based on the wadding, all else the same
 

hanshi

Cannon
Joined
May 7, 2009
Messages
13,296
Reaction score
7,150
Location
New England
Several years ago I chronographed my .40 with a variety of loads; didn't know I was in for a shock. The barrel is only 38" but with 60 grains of Goex 3F it gave a reading of 2140 fps. That load was very accurate at 100 yds as well. I had recently changed some components which is likely the reason for the higher speed. On a previous session prior to the change in patching/etc 60 grains gave 1950 fps from the 38" barrel.
 
Top