I started reloading as the way to afford the sport. And of course the questions come along with it. I have read a few forums around the net about burnt casings and everyone says it is caused by under loading creating a poor seal. All of my 45 acp reloads are coming out with burn marks on about 1/3 of the case using a Hipoint and an MPA 10SST. Factory shots are clean. I am using 230 RN with Hodgdon Longshot. The Longshot loads go from 6.0 to 6.8 so I loaded up some 6.4, 6.6 and 6.8. All the brass from all three loads in both guns had the same marks. So I went with some single loading so I could identify 6 o'clock on the round and the results are that all the burn marks are all on the bottom were the powder lies in the casing. So I rotated them 180 and the burning went away :laugh:. Conclusion: the burn marks are not from poor sealing (that's a guarantee with the 6.8) but are a hot spot where the powder lies and burns. The next step it to load some with 800 x or HS-6. Is this a powder problem? Is it preventable? It is not enough to damage my brass but factory loads run clean. Suggestions?