It seems to be priced by the geometric mean of volume and weight. The square root of the square of 9 multiplied by the square of 16 (the weight of normal powder you could put in the same jar) is 144. Divide by 100 to get 1.44. Divide the price of Trail Boss per pound by that, and you have a good price for a normal pound of powder. Or, square 16 and divide by the square of 9 and take the square root of the result (1.777…) and multiply that by the price of Trail Boss to get the price per pound of Trail Boss.
Joking aside, it is the cleanest powder I ever ran, though; at least it is with heavy bullets.
Alliant's current data puts 4.7 grains as maximum for an LSWC at standard pressure and 5.2 grains for +P maximum. For 125 grains for a Gold Dot HP, it is 5.7 grains and 6.0 grains, for standard and +P maximums.
Everybody's old load data was developed in production guns while watching for pressure signs. As pressure measuring equipment has come to be considered important for liability reasons and the makers have either acquired their own test equipment or borrow it or contract the testing of their pressure sign-developed loads outside, many of those old loads have turned out to be higher in pressure than originally thought and have been adjusted down.
Additionally, the load manual authors have developed a practice of not letting the top load out of a test run of 10 shots run over the SAAMI MAP. This is why the pressures listed for maximum loads don't match. The powders that had more variation get a lower maximum pressure to keep the warmest load in a 10-shot average from running over SAAMI MAP. That has the advantage for a person choosing a powder to pick one that has a lower pressure variance than the rest by picking from among those with the highest maximum load pressures.
But the above is not how the MAP is designed to be used. It's supposed to be a limit for the average peak pressure for the ten shot test, not a limit for the single highest pressure shot out of the ten. But the load manual authors know not all the powders they list are the most appropriate for the cartridge and bullet and primer combination. They are listing some just so more shooters can use something they have on hand, even if it isn't optimal. The result is wider pressure variation in the less appropriate powders than the SAAMI standard allows, and they figure to give themselves some safety margin with the way that is done anyway.
A statistical shortcut:
Look up the MAP (CUP MAP or psi MAP, whichever unit the load data pressure is given in) for your cartridge in the appropriate SAAMI standard. Multiply it by 0.938 for cartridges listed in the centerfire rifle standard and by 0.923 for those in the centerfire pistol and revolver cartridge standard and by 0.885 for those in the shotshell standard. If the result is greater than the maximum pressure listed by the load data source, the chances are strong that particular powder cannot be loaded to the SAAMI standard average pressure method without seeomg pressure variation that exceeds SAAMI's pressure SD limit (4% for rifle and 5% for handgun cartridges and 7.5% for shotshells).
