Ballistic numbers

[Don]

Gents,

For some time now I've been baffled by the wide differences in ballistic numbers related to cap and ball revolvers. Some charts have a charge of 25 grains of 3f bp creating velocities in the 600's while another will put the same charge and same powder in the 800's. Yes I know some brands of bp are slower and some faster and some brands of revolver are the cause of some variences but why hundreds of feet per second? I can understand maybe 50 to a 100 fps but more than that I don't understand. Do chronographs vary in their readings that much. I just want to know who's numbers to trust.

Thanks

Don

 

Tempature, humidity, altitude, Powder brand, amount of filler and compression, burned out LEDs on the digital screen (8 becomes a 6).

Lots of variables to this BP thing.

 

[CoyoteJoe]

You'll find a lot of variation in loading data for cartridge guns with smokeless powder as well.
Even with the best laboratory equipment data will vary from day to day. Add in different guns, different equipment, different brands of powder and different testers (not to mention "indifferent" testers) and you have a lot of variables. :grin:

 

[biliff]

Besides all the other stuff mentioned there's also the barrel/cylinder gap to contend with. Also some C&B revolvers have chambers that are less than the barrels groove diameter. Doesn't make for a real good seal going down the bore. Lots of potential for wild swings in velocity.

 

From reading your post I suspect you are a reloader, and/or pay attention to published ballistics. I reload fervently but absolutely will not give much credence to any published ballistics whatsoever. If you've perused the various reloading manuals and pamphlets published by the manufacturers of propellants and bullets you're no doubt aware of the vast discrepencies in their data. Black powder is no different. If you want the most correct data you can get, acquire for yourself a good chronograph and run your own tests. I don't believe most chronographs are any less accurate than they advertise. The variables come from differences in lots of powders, the enormous differences in firearms, variances in bullets, primers, balls, patch thickness, ad infinitum. Don't be so foolish as to read a listed ballistic from any entity and expect it to be reflected in your particular firearm, or in the same firearm from another entity. It simply isn't going to happen. The variables are too great, as has been stated.

Vic

Vic

 

[Slamfire]

Another thing I've noticed is that it takes a 200 fps increase to make a difference of 25 yards in maximum point blank range. Them figures are for suppository firearms. I haven't tried to check any of my muzzleloaders ballistic arcs. :winking:

 

[Zonie]

"Them figures are for suppository firearms."
_________________________________________________

Which reminds me of the story of the man who was, should we say, somewhat plugged up.
It got so bad, he finally went to the doctor.
The doctor gave him a perscription for some suppositories and told him to come back in a few days.

Several days later the man walked into the doctors office and the doctor asked "Did the medication I perscribed fix the problem?

The man answered "For all the good those things did, I should have shoved them up my A**."

:rotf: