Thanks for all the advise. I guess when I'm cleaning, a little grease won't make a difference. I didn't have a problem a while back. Trying to shoot off some left over 4227 and as expected a misfire. No matter what I did it wouldn't go BOOM :x . I had to pull the gun apart, take out the breech plug. You guessed it, powder all over the threads and grease. Spent considerable time trying to clean it at the range. I finally put the breech plug back in and I think and grains of powder got pushed forward in the threads.