I reloaded for years without cleaning/deburring the flash hole. Then one day while at a gun store, I was looking thru the reloading stuff, and decided to buy a deburring tool. I also got some chunks of brass out of the casings, but did it improve the accuracy from what it was before? Not in my mind, it didn't. As was said before, a lot of reloaders get pretty anal about their procedures, and I'm one of them. The deburring didn't help one bit in my mind, but I'm gonna continue to do it, because it sure doesn't hurt,and yes, it only takes a few more seconds/case. I do feel that primer pocket cleaning is mandatory, however....