Strange Noise

[Michael J. Spangler]

Every once in a while I get a weird whizzing noise when I fire my 1874 Pedersoli Sharps or my 1884 Trapdoor.
I first noticed it with paper patched bullets and figured it was a patch hanging onto the bullet and the tail making the noise. Or maybe an undersized core tumbling strangely.
Tonight I had it happen with grease groove bullets too. Kind of weird.
Any ideas? Single shot gremlins?
On a side note I had a ton of fun shooting at the 200 and 300 yard steel tonight. I just wish they were painted better. I couldn’t see the 500 yard steel unfortunately.
I’m considering buying a bigger gong and popping it out at 500.

Thanks for looking!

[nun2kute]

"Sounds" FUN ! [smilie=l:[smilie=l:[smilie=l:

[1Hawkeye]

Sounds like your rounds are tumbling as they are going down range. If when you hear that kind of buzzing sound do they even hit near the target? It could be they are not stabilizing the trick is to find out why. It might be the bullet design,diameter,hardness,or velocity. When your done shooting is the bore badly leaded? What bullet are you using and at what velocity?

[Michael J. Spangler]

I was thinking stabilization could be the issue but why only one out of every 10 or 12 ?
Either a Hoch nose pour 550 grain or a Lyman Postell 535 grain.
Anywhere from 12 grains of unique to standard pressure Trapdoor loads using rifle powder.

[country gent]

The Pedersoli Sharps should be a 1-18 twist and both those bullets should stabilize in that twist. The trap door may be 1-20 and they may be a little long in it. I would possible see a PP that sticks or partially unwraps singing to you.

Do you use a base wad of any kind under the bullets? It may stick to the base of the grease grooved bullet and cause this also.
Wipe the bases of the GG clean and dry if your using a heavy wad try adding a tracing paper or this newspaper wad between wad and bullet. Make sure sprue cuts are smooth and flat.

[shutinlead]

Everything mentioned above- but I'd stress checking your bullets- visually filled out, no voids or rounded corners on the grooves? if the bullet isn't round -the spin as it leaves the barrel doesn't have much of a chance of rotating around it center axis. Lube and leading is the next thing to focus on.
As for the paper patched - I'm fighting that right now - bullets from one gun never give me any issues, the same bullets in a different rifle, calibers the same, bore slugs the same within a few tenths shoots and sounds a bumble bee. Can't keep it on the target frame at a 100, but they both shoot greasers nearly the same... and remarkably accurate...

[Gunlaker]

When you are in the pits pulling targets you can hear an unstable bullet going by. It makes a fair bit of noise, kind of like buzzing. The stable ones that miss the paper are completely silent, as long as they are subsonic.

Chris.

[1Hawkeye]

Might be that every once in awhile one bullet under sized or not perfectly round or just not pushed fast enough. A 500 gr service load is going around 1185 feet per second so my guess would be if the bullet quality is dead on then you need to push them at say 1200/1225 fps.

[Dan Cash]

If you hear your bullet going away buzzing, it is tumbling or at least yawing violently. If the bullet fits the bore and is traveling fast enough for normal stability, such yaw or tumbling comes from an out of balance bullet.

[Michael J. Spangler]

Ok so I’m going to load some more with a higher velocity and see if that solves the issue.
The slower speed would make sense.
I don’t know what the ES is on using unique with a 550 grain but I’m guessing if it’s teetering in the edge of stability that could be the culprit. I could load a few more and told the cartridge forward or backwards to set up the ignition better and worse to see if changes the velocity.
Either way I think I need a new powder to get some higher velocity.

[dubber123]

I heard the same thing when I first started loading for an 1874 replica. I couldn't figure it out until I got a perfect side profile of a boolit on paper. Once I scienced out that problem, no more noise. Groups amazingly improved dramatically too.

[1Hawkeye]

Unique is a great powder in the .45-70 from collar buttons up to the 500gr lyman 457125 but for the heavies you might want to try IMR 3031 or if you still have some SR 4759.

[waksupi]

I agree that the bullets are tumbling. Back when I was just starting in with BPCR, I had a Martini Henry. I was experiencing the same thing as you, and took me awhile to get clued into the problem.