Energy Calculations

[tn_junk]

I am interested in calculating the amount of energy in a given amount of any type (or brand) of powder.
Is there a data table anywhere that provides this base information? I could "guestimate" some numbers by working back from bullet weight/velocity on a straight walled cartridge, but would much prefer some solid data.
Have cruised the 'net and found nothing that suits me.
Anybody got any ideas?

thanks

alan

[deltecs]

I'm not sure I understand the question.  Energy per grain of powder?  Energy per grain of powder in a given time frame?  Potential energy per grain?  Energy under compression and how much compression?  I think the variables are too large to accurately determine energy per grain within the cartridge on firing.  Case configuration, primer variances, flash hole size, powder column length, bore diameter of the projectile, bullet weight, crimping or lack of, distance bullet is from lands, tight or loose chamber dimensions, and quite a few other variables influence powder ignition and energy derived from it.  I'd hate to depend on any calculations with any accuracy or confidence of interpolated powder charges based on energy levels possible solely.  This is asking for trouble with a capital T.

[tn_junk]

I'm not sure I understand the question.  Energy per grain of powder?  Energy per grain of powder in a given time frame?  Potential energy per grain?  Energy under compression and how much compression?  I think the variables are too large to accurately determine energy per grain within the cartridge on firing.  Case configuration, primer variances, flash hole size, powder column length, bore diameter of the projectile, bullet weight, crimping or lack of, distance bullet is from lands, tight or loose chamber dimensions, and quite a few other variables influence powder ignition and energy derived from it.  I'd hate to depend on any calculations with any accuracy or confidence of interpolated powder charges based on energy levels possible solely.  This is asking for trouble with a capital T.

I totally agree with you that there are many, many variables. That's why I don't have any intention of trying to extrapolate data from loading tables. And my intention is not to try and load "hot" loads. I am instead looking at using some slower burning powders in reduced velocity loads with cast bullets. All the data I have seen is for extremely fast powder with a very light load. I am thinking of a slightly higher load of a slower burning powder to get the same FPS with a smaller pressure peak.
Just a wild idea that I will do A LOT of work on before I actually load any rounds.

alan

[jhalcott]

  have you asked about this on the cast bullet forums? Just what powders in what calibers are you going to load. Also what weight bullets? The best info you might get is a relative burning rate chart. This ONLY tells you that one powder is faster/slower than the next.

[deltecs]

THIS IS NOT A RECOMMENDATION.  If one looks closely at relative burning rates of powder and volume used in a particular case with the same bullet, one notices that it GENERALLY takes more grains of slower burning powders to obtain similar pressures.  One might be to load a slower burning powder with the same grains of a faster burning MINIMUM load and chronograph it.  I don't recommend this procedure whatsoever and find it to be exceedingly dangerous.  Any attempts to substantially deviate from published loading data for a cartridge is asking for trouble.  I admit that I've done this for rounds having little or no published load data, however I have used very similar case style and capacity of known load data as a starting base and cut it 15% to start.  I've also micrometer checked base and case expansion on every shot and load, chronograph velocity, and increase load volume in 0.5 grain increments until I've got the accuracy or sweet spot for the bullet weight I'm shooting, not necessarily at maximum velocity.  I've gotten over the mostest velocity and pressure for a given round early in my youth, thankfully.  I don't need to stress the action or cause myself any injury should brass fail or metal fatigue.  The .35 Whelen is a case in point.  Most have a 1/12" twist and load data generally uses faster powders for a given bullet weight.  The 338-06 in the same bullet weight uses slower burning powders that can be used for loading in the Whelen with custom rifling at 1/10".  Even with the bigger bore diameter, do not attempt to increase velocity above the .338-06 as SAAMI pressure limits are already high for this round and any significant velocity increase will have a corresponding pressure increase possibly above safe limits.