Effect Of Powder Compaction On Muzzleloading Velocities

[Falcon]

For a long time i've been aware that velocity goes higher when a powder charge is compressed. This was recently confirmed when a friend and i tested Alliant Black MZ using his Oehler 43 personal ballistics lab and my TC Encore rifle.

This gentleman took his testing much further. He got an increase of over 100 fps when the powder charge was compressed. His charge was 30 grains of Swiss BP driving a PRB. He also proved that a low standard deviation for velocity is not everything:

Compressed Loads

Since compression is hard enough to judge, I decided to test only four variations:

• 'Loose' - The ball placed 1/4" above the top of the powder.
• 'Normal' - The ball seated with about one pound of pressure.
• 'Compacted' - The powder compressed hard, then the ball seated.
• 'Whanged' - The ball and powder compressed together.

[frontiergander]

that makes sense with that bulky american pioneer powder. The only way to get APP to shoot good was compressing it greatly and cleaning/oiling the bore to keep velocity faster.

[quigleysharps4570]

Good read falcon. Still goes right back to consistency too. ;)

[tomlightfield]

Good post and info, very interesting results.

[BruceBruce1959]

Originally Posted by FrontierGander

The only way to get APP to shoot good was compressing it greatly and cleaning/oiling the bore to keep velocity faster.

oiling the bore while shooting isn't a good idea at all, a weapon should always have a clean dry bore before firing,
oil can create increased pressures in the barrel which could turn into a fatal incident.
the Bore should only be oiled while being stored in a Gun safe/cabinet..

[frontiergander]

until you shoot APP over a chrono, you havent a clue what APP likes and doesnt like. Oiling the bore after each shot and then running a dry patch to mop it out keeps the velocity a great deal better in consistency.

[Hunting Man]

While I do not have any input to the powder used, I will say anyone who intentionally seats a bullet ahead of the powder charge is a disaster waiting to happen. The bullet in this case acts as a blockage to the powder explosion and has caused many a barrel to explode. Do not under any circumstances ever, never, seat your bullet with a gap between it and the powder, it may be your last time period. If your lucky you may have both eyes and hands and most of your face left. Always seat the bullet firmly on the powder charge. When using pellets do not crush them just seat the bullet firmly on top. You will stay out of trouble by following this simple yet important rule. This practice has been the golden rule for obvious sound reasons. Please do not break this rule!

[BruceBruce1959]

Originally Posted by FrontierGander

Oiling the bore after each shot and then running a dry patch to mop it out keeps the velocity a great deal better in consistency.

oiling the bore after each shot even if you do run a dry patch is only asking for trouble.
if you oil the bore, then run a dry patch, then charge with powder, even the slightest oil residue left behind can contaminate the powder.
I learned this years ago from my own trial eand error practices, any form of Black powder can easily become contaminated.
I'm just wanting to warn others about my own experiences while using Black powders,
So personally I would not recommend oiling a bore between shots and,
i'm quite certain oiling the bore while shooting does absolutely nothing to improve accuracy but oiling does preserve and protect the barrel during storage.
As a matter of fact, while in the military I remember getting a good butt chewing because my bore was oily. (according to him)
but patch after patch it appeared Dry enough to me but my DS, wasn't liking it at all at the time. JMO....