While I have smelled some strange by-product outgassing from plastics, including those Xcelite nut driver handles that smell like vomit if you bump them with a soldering iron, but if that was the contributing factor, I would have expected to encounter it in my bottle of Hodgdon H322, Benchmark, H335, H4895, H1000, H4350, etc, especially the double base ball powders. When I got home, I whiffed on charging pans of each the new and old Lil Gun and they are distinctly different. Rest assured, I will load up some 38gr under 250 FTX loads and something lighter, like 200 FTX to see how they track.
+1 on the Bomb Calorimeter. That's the right way to assess this stuff. We used one in college chemistry class, to measure the calorie content of sucrose, just to get a feel for how one works. That was like a couple of light years ago!
Hoot