I just finished burning a bunch of old powder that I had in the workshop/barn. its was about 3 lbs made with poor charcoal this summer, fun. I don't like clutter.
The stuff made with good charcoal I keep, I can increase the milling and turn it into my latest highest performance stuff.
I just finished another batch today to see if I could replicate the great performance from the last batch and I did and slightly surpassed it. It was made almost the same way except that I purified the KNO3 and milled with a higher RPM for as long as I could in one day. I started in the morning at about 9 and finished at night at about 9:30. This was with the much higher RPM Mill. I did a lot of burn tests to verify if it was good during the process. In the end it was quite good with only 4 or 5 specs of white in the residue. This is a 76/14/10 mix. This is with the same accurate 46-247C bullet I had made with larger dimensions, that weighs 250gr. In the SAA, 7.5 inch barrel. 30 grains weight. This powder has 1.6 g/cc pucks and weighs 27 grains for a powder measure set at 30 grains.
Now I hate to boast, but swiss needed 35 grains to reach this velocity with a 35 "grain" volume mine did it with 30 grains and a 33 grain mark on the volumetric scale...just saying.
Attachment 292276
Im not sure purifying the KNO3 was worth it with the duda diesel stuff. But it did make very fine crystals. I think that milling the powder efficiently and at an optimal RPM is key. I use big .570 high antimony lead balls now and clumping is no longer a problem as it was before but every 2 hours or so I still stop the milling and tap the jar, shake it and start it again. Some small amount still find its way into the corners. I have yet to try it in the rifle, but I think it should be quite good. I also seem to be getting the same or better velocity with a lee 452-255-RF. So more weight and higher velocity, could be that the powder has a maximum velocity or burn rate and it dosen't slow down for larger projectiles. I could even increase efficiency due to higher pressures...someone please chime in on this if you can.