Powder compression

[Martini2]

Hello Kurt, It is cool and wet here in Midwest too. So I'll speculate on this combustion think. Essentially were talking about a confined burn of fuel/air mix. There does exist a test used to determine the BTU content or release of components, believe it called "Closed Bomb" test. The key thing is the heat and rate of combustion is quantified. Such a test would yield measured proof of loose VS heavily compressed charge of same weight. Empirically your photos (very good) show less smoke with less compression however are there any other details you gathered like chronograph data to illustrate charge efficacy? Also would it be possible to spread a white sheet under path of rifle fire to check for ejected unburnt powder etc. I suspect these photos do show like you say the packed charge may be driven out of barrel in part adding to the visible smoke. A paradox maybe that the hot end of the highly compressed charge burn slightly more efficient thus still increasing velocity or scrubbing previous residue from bore. Veeery Interesting