I made up some reloads for the very first time today with H4350 in my .243 The loads appear to function correctly and have a very mild recoil (not that a .243 is punchy anyway) but it is really quite smoky. I'm talking a discernible cloud of smoke. At first I put it down to the Napier burning off from the mod, but it continued through all 8 test rounds I fired.
I inherited the powder and I've had it 2 months. Could it be the powder degrading?