Optimal powder load

[zimmerstutzen]

There's all kinds of formulas and mathematical explanations that apply to shooting.  Why do bullets go high when shooting down hill and up hill?  Why do bullets fall and at what rate, ballistic co-efficients, pitch yawl, air drag, etc.   Most of these understood and studied extensively at the beginning of the 19th century by folks far more familiar with shooting than most of us.    Even down to the standardization of granulation size.  

For those who say "powder make gun  boom", formulas and mathematical explanations and study is meaningless.  For those who are happy rubbing sticks together to create fire, that is fine.  Some of us have figured out how to use more technologically advanced and easier ways to accomplish the same goal with better control and more consistent and accurate results.  

Shooting inaccurately may be fun to some.  Not to me.  Some folks shoot only as a means to hunt.  Minute of deer is all they are concerned with.  Some of us actually care about trying to beat MOA with round balls and front stuffers.  

Bad science comes from merely saying something is proven false, rwith no back up.  Just make up facts out of thin air and pose them as proof positive.  The formula has limitations as all do.    I certainly never said it was finished science.  

On another thread we got folks to post their caliber, barrel length and best precision paper target load.  A majority of the loads posted were within 5 or 10 grains of the results that would have been found by applying the Davenport calculation.  That isn't just coincidence.  It is verification.    

  

[BrownBear]

Explain how it takes larger and smaller calibers into account.  We keep hearing reports that it doesn't work for them. 

And while you're at it, define optimum.

Davenport probably was a real good guy, but you're doing a real disservice to his memory in trying to stop evolution of his formula.  That's the pseudoscience, and it's on you rather than him.

[roundball]

This whole modern keyboard theory defense smacks of a troll topic to me...has nothing to do with traditional muzzleloading...this topic already got slam-dunked by the traditional membership of another forum...now its reared its head over here

[hanshi]

I don't like math and I don't like formulas.  I file my sights by trial and error and find my loads by shooting and comparing.  I'll sometimes chronograph loads but in reality I'd just as soon not know how fast they're going.  I figure the best top loads will come out fairly close to the formula prediction.  But guess what, the best load from range testing will be exactly on the best load.  Can't beat that!

[zimmerstutzen]

Brown Bear, you obviously did NOT read my first post in this thread.  I never said anything about ceasing to study or about NOT correcting for very small and very large calibers. 

I said Davenport was on the right track.  That the formula skews off for the extremes in caliber.   A load for  a Brown Bess calculated under the formula would be unsafe.    Davenport recognizes that powder burns at a particular constant rate for bore diameter and length and arrives at a result by calculating the volumne of bore times a powder constant.  For very small and large calibers, I suspect that the powder burns at a slightly different rate.  For instance putting 50 grains of powder into a 28 cal bore, would (again I suspect,) burn more like a fuse over the few inches of bore such a charge would occupy.  Likewise in a large bore, a higher charge of powder takes up less inches of bore space.   A larger portion of the powder can be consumed in the first inch of a 58 cal  bore, than for instance in a 28 cal.     Davenport relies solely on a burn rate constant x cubic inch of bore.    I personally feel there is another variable that needs to be incorporated to account for the differences at extremes of bore size.    The same was true for the Greenhill formula for determining a stable bullet length  for a bore with a known twist.  Certain erratic features of Greenhill's formula   were corrected by factoring in velocities.   

Some folks shoot a rifle and are happy.  Most muzzleloader enthusiasts realize that there is a difference between round ball rifling and conical bullet rifling.    very few make any attempt to understand the differences in rifling and twist beyond that.  Depth and width and shape of grooves, the width of grooves as compared to lands, and what configuration of rifling is more accurate for  rest shooting .  If you have deep square grooves is one type of patching better than the standard commercial cotton drill sold in the stores?,  I suppose some would say it takes the fun out of shooting to study such mundane things.  Personally, whatever it takes to shoot better groups is what makes shooting fun for me.  I am trying to find a barrel maker to cut slow twist Alex Henry style rifling for a muzzleloader gun, but so far no takers.   

[Dphariss]

The Davenport formula is BS so far as determining how much powder a bore will burn.
This is easily proven with a Chronograph.
A Chronograph may show that it will give the point of diminishing returns. But its not going give the powder a bore will burn. Too many variables.
Big bore rifle balls have more inertia for the bore size than smaller balls. This will change the formula.
The bore fit, the land groove ratio the smoothness of the bore will ALL effect how much a bore will burn.
Then there is powder quality. Look at the powder charges needed with the C&H used in Lyman's first BP loading manual. It was a very poor powder, coarse ground, slow burning, similar to blasting powder, and still at charges of 150-180 and more it was still producing velocity increase in "medium bore" rifles. I bet a bore will burn about twice as much swiss.
Then we have the powder as part of the projectile weight. Here the more powder you shoot the more inertia and the better the barrel will use the powder since the projectile accelerates slower and initial burn is higher pressure. More powder is consumed moving the mass. Then we have to ask does this cause a velocity increase even if the powder is not all burnt in the barrel?

The shoot over a sheet thing is almost to silly to recreate. I shot a 32" 32 caliber Douglas barrel once over sheets in a building and never found ANYTHING I could say was powder. FFF  Dupont 65 gr, 0 buckshot with a ticking patch, nothing on the sheets. I picked up the sheets and quit at 65 grains. This would be like shooting about 300 grains of powder in a 54 based on percentage of ball weight.
Then we have to ask "how far do powder granules fly at 2000 fps?
Have they been crushed or broken by the pressure forcing them against the patch and ball.?
This might then REDUCE the burn rate. This could be the case if the powder is pulverized and forms a more or less solid mass at the bullet base. Or it might increase the burn rate if simply broken into smaller granules.

I would not waste powder testing it.

Dan

[54Bucks]

 I think I'll wait for a lot more info. before forming an opinion on this subject or a load formula. I'll also pass on only using maximum loads and 100yd. bench work for proof of anything. Perhaps ignorance is bliss.

[hanshi]

 Perhaps ignorance is bliss.
[/quote]


What you don't know ain't gonna cause you worry.

[Daryl]

Ahh - but bench testing at 100 yards will certainly prove or disprove a load's accuracy - very quickly.

[54Bucks]

 Could prove a lot of things like the magnification of shooting error. I find a shorter distance gives me a better indication of sight picture in relation to the target when the shot breaks, and how my gun groups when using open sights. A chronograph and trajectory estimates using god forbid some math fills in the rest of the info I need for possible longer ranges.

[zimmerstutzen]

Dphariss said:"The Davenport formula is BS so far as determining how much powder a bore will burn."

That isn't what the formula is for and Phariss well knows that.  It is a short hand way to arrive by mathematical calculation at the powder charge with the best pressure and velocity return per grain of powder.  Of course a chronograph will also show that, after testing several dozen loads over a space of hours.    Instead of floundering around testing loads far outside the range of "optimal" why not just zero in.  

Nobody ever said it was to determine how much powder a bore will burn and such statements either demonstrate a failure to comprehend how a charge burns in a barrel or an intentional effort to misstate the purpose of the formula.  

Consultation with manufacturers' maximum load data shows that far more powder will burn in a barrel than the formula calculates.  That alone demonstrates the lack of comprehension of the formula by the author of that statement.

Any idiot knows that dumping more powder in a bore produces higher velocities and flatter trajectory for HUNTING.  Most folks are aware that the most accurate paper punching target loads are far less than the manufacturers maximums and in most cases less than hunting loads.  How in light of that, could anyone make the missstatement that the purpose is to determine the limit of powder charges that will burn in a barrel.  

[roundball]

The Davenport formula is BS so far as determining how much powder a bore will burn.

The shoot over a sheet thing is almost to silly to recreate.

Correct on both accounts...I'm sure there is some amount of old wives tales associated with every hobby, but I have to say I haven't experienced any hobby in my life where so many old wives tales abound like they do in this grand old form of shooting traditional styled muzzleloaders.

But the larger issue is the waste of time and Internet bandwidth trying to use logic and real experience with keyboard theorists as they just don't get it...or, they do...and they secretly really just need attention.



Wait.....what's that noise overhead.....Oh, that's just Davey and Daniel laughing...
    

[zimmerstutzen]

As pointed out above roundball, Phariss's statement was demonstarted to be quite wrong just by a comparison of manufacturers' max load data to the formula.  

And the shooting over the sheet thing,  well.   I worked at a range and full well know about the unburned  powder expelled from the muzzles of guns.  (Real world experience by the way!)  I know from experience that such unburned powder can be gathered up and burned.    

[Rasch Chronicles]

You know fellows, I do a lot of wondering.

It occured to me, that if you light powder off from the back end, it stands to reason that the fromt part of the powder column will get shoved before it can light up. Maybe it moves too fast, and stays just ahead of the flame front. If it was lit from in front, it would all have to stay in the breech.

Just thinking... I could be wrong. You guys know more than I do about this. I really don't know how blackpowder ignites and reacts inside of a barrel.

Best regards,
Albert “Afghanus” Rasch
The Rasch Outdoor Chronicles™   
Hog Sticking Raj Style! Pt I

[zimmerstutzen]

albert, there were some experiments in the early 1800's to ignite the powder from the middle and even front of the charge.    The problem in lighting from the front, is that the flash channel can create a place for the ball/bullet to hang up if accidentally dry balled.    I suspect that underhammers and side slappers may get faster/more complete ignition of the charge because the flame is directed into the main charge instead of traveling the contorted flash channels found in some side lock guns.   Look at those hollow pellets for inlines and the way the flash must spread up through the hollow on ignition.    That is certainly not a new idea.  In some old artillery shells from WW2 and before, the pwder charge surrounded a metal tube centered over the primer.  That tube had holes along the side every inch or two so the flame of the primer was introduced to the charge at several places along the tube at the same time.   ie ressulting in more complete and faster ignition.    So, the thought that occurred to you, also occurred to some of the best government ballistics experts of the past two centuries and actually resulted in some different mechanical means for accomplishing better faster ignition.  It is part of the reason for the hollow pellets on the market.   and for the design of the primer tubes in WW1 and WW2 artillery shells.

[Rasch Chronicles]

Elmer Kieth mentioned in some book I owned that when he and the other fellows were experimenting with the 333 OKH, they tried the same thing, a tube to light off the propellant from in front of the cartridge.

It was pain to reload...

Best Regards,
Albert A Rasch
The Rasch Outdoor Chronicles™
We Build a Pirogue!

[Daryl]

You know fellows, I do a lot of wondering.

It occured to me, that if you light powder off from the back end, it stands to reason that the fromt part of the powder column will get shoved before it can light up. Maybe it moves too fast, and stays just ahead of the flame front. If it was lit from in front, it would all have to stay in the breech.

Just thinking... I could be wrong. You guys know more than I do about this. I really don't know how blackpowder ignites and reacts inside of a barrel.

Best regards,
Albert “Afghanus” Rasch
The Rasch Outdoor Chronicles™   
Hog Sticking Raj Style! Pt I

Modern guns, nothing to do with our guns.  Prodex or T-7- whatever need the holes etc - again, nothing to do with our guns.

I do not for a second, believe that unburnt black powder spews from the muzzle of a ML rifle - with any sensible load.  That therefore means I do not believe the 'stuff' that is spewed can be burnt - you can use my hand.

Smokeless powder can leave the muzzle in a condition that will allow further burning. Nothing to do with our guns.

[David R. Watson]

I saw those preforated primer tubes used in Viet Nam.
The idea about front ignition or rather not normal point of ignition can be observed by reading about the Ultimate Muzzleloader made by Ken Johnston. His primer ignition will burn 200 grains of pyrodex in the first 9.5" of barrell and it will detonate the four 50 grain pelletts of pyrodex at 52,000 psi.
Before someone says Bravo Sierra - I am a "certified" explosives instructor and have taught just about every high speed military team in our country as well as most of the Baltic countries...not bragging, but simply trying to say that Ultimate is taking a low order explosive and getting it to display high order characteristics every shot simply by the ignition system. I had to be convinced - and was.
I have fired 1.5" three shot groups at 300 yards and was pushing a 300gr SST at 2380fps when this as done. It's not a flinter so I don't shoot it unless asked to demo it.

[ironwolf]

  A sheet of paper don't know how fast a ball is travelling.  Leave the chronos for the scientist and test the gun for accuracy with different loads, patches and balls.

  KW

[Daryl]

 A sheet of paper don't know how fast a ball is travelling.  Leave the chronos for the scientist and test the gun for accuracy with different loads, patches and balls.

  KW

Ultimately, exactly, KW.  One must test.  Not all guns respond to the various formulas although some do.

Well, David, nice to hear about the explosive's experience. Could come in very handy for us in the future.

[Daryl]

I've cleaned up what appeared to be the personal attacks. Here, we can discount a thing- ie: formula in this instance, but not people. Everyone is entitled to an opinion.

For example - stating the formula is wrong or flawed is OK.  Stating Devenport doesn't know what he's talking about, is not allowed as that is a personal attack.