paulvallandigham
Passed On
- Joined
- Jan 9, 2006
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BB: That was my experience with my .50 rifle, using 2Fg and 3Fg powders, until I tried the .50 cal.( .510" diameter) Vegetable Fiber Wads( Walters) using the 2Fg powder.
My brother bought some .40 cal. Fiber wads to try at the same time, as he was testing Goex 3Fg powder vs. Swiss 3F powder. His chronograph told him he was getting higher velocities using ONLY a PRB in the gun with a same-volume load of Swiss powder. But, when he used a VF Wad under his PRB with both Goex and Swiss powders, the difference in velocity Narrowed considerably, and the SDV dropped into single digits with Goex!
The unexpected side effect was that using the OP wad with both powders caused the BP residue in his barrel to be so similar he could not tell the difference, by feel, or visual examination of his cleaning patch. He has since increased the size of the ball diameter he is using, and finds more efficient(complete) burning of the powder, with and without the use of the OP wad.
Pressure rises, with more time in the barrel for the powder to burn.
You achieve this two ways: using an OP wad, that offers resistance, and delays the movement of your PRB forward in the barrel; and by increasing the powder charge you use. People tend to forget that more powder ADDS MORE MASS that has to be moved by the gases developed as the powder burns. That Added Mass also delays the movement of your PRB from its seated position in front of the barrel, but to a lesser extent than a soft OP wad. The difference between the OP wad and a heavier powder charge, is that the powder BURNS as the pressure rises, creating more gas, and both MORE pressure( more gas in the same space) and hotter temperatures behind the PRB before the PRB moves.
This later phenomena is why BP guns tend to have "TWO" pet loads, one using a light charge that is very accurate, since it vibrates the barrel very little, but uniformly. The other is a heavy charge, often used for a " Hunting Load", that reduces "Barrel Time" for the PRB by increasing its velocity. The reduced barrel time also vibrates the barrel, but the vibrations are so fast that they disturb the POI less. The heavy powder charge ALSO upsets RBs, no matter their composition( within reason) to fill the grooves and provide a consistent seal in the barrel.
Its the heavier powder charge that allows us to shoot swaged alloy lead balls well, when lesser charges don't produce good groups, and often result in an occasional "flyer" on target. Flyers are the result of incomplete sealing, usually because the patch is not properly lubed, or the patch is undersized for the groove depth, and ball diameter.
When shooting Swaged lead balls, or cast balls from other than pure lead, the sage advice to get better accuracy with these balls has always been, "Increase the powder charge by another 5 grains and see if that doesn't improve matters. If not, add more powder!" :thumbsup:
My brother bought some .40 cal. Fiber wads to try at the same time, as he was testing Goex 3Fg powder vs. Swiss 3F powder. His chronograph told him he was getting higher velocities using ONLY a PRB in the gun with a same-volume load of Swiss powder. But, when he used a VF Wad under his PRB with both Goex and Swiss powders, the difference in velocity Narrowed considerably, and the SDV dropped into single digits with Goex!
The unexpected side effect was that using the OP wad with both powders caused the BP residue in his barrel to be so similar he could not tell the difference, by feel, or visual examination of his cleaning patch. He has since increased the size of the ball diameter he is using, and finds more efficient(complete) burning of the powder, with and without the use of the OP wad.
Pressure rises, with more time in the barrel for the powder to burn.
You achieve this two ways: using an OP wad, that offers resistance, and delays the movement of your PRB forward in the barrel; and by increasing the powder charge you use. People tend to forget that more powder ADDS MORE MASS that has to be moved by the gases developed as the powder burns. That Added Mass also delays the movement of your PRB from its seated position in front of the barrel, but to a lesser extent than a soft OP wad. The difference between the OP wad and a heavier powder charge, is that the powder BURNS as the pressure rises, creating more gas, and both MORE pressure( more gas in the same space) and hotter temperatures behind the PRB before the PRB moves.
This later phenomena is why BP guns tend to have "TWO" pet loads, one using a light charge that is very accurate, since it vibrates the barrel very little, but uniformly. The other is a heavy charge, often used for a " Hunting Load", that reduces "Barrel Time" for the PRB by increasing its velocity. The reduced barrel time also vibrates the barrel, but the vibrations are so fast that they disturb the POI less. The heavy powder charge ALSO upsets RBs, no matter their composition( within reason) to fill the grooves and provide a consistent seal in the barrel.
Its the heavier powder charge that allows us to shoot swaged alloy lead balls well, when lesser charges don't produce good groups, and often result in an occasional "flyer" on target. Flyers are the result of incomplete sealing, usually because the patch is not properly lubed, or the patch is undersized for the groove depth, and ball diameter.
When shooting Swaged lead balls, or cast balls from other than pure lead, the sage advice to get better accuracy with these balls has always been, "Increase the powder charge by another 5 grains and see if that doesn't improve matters. If not, add more powder!" :thumbsup:
