I'm considering an ultrasonic cleaner but I'm having a hard time finding good data on the impact of having clean interior brass. I don't really care about having clean exterior brass because it is pretty to look at. I'm only interested in improving my shooting. I found many threads on what works the best to get the cleanest cartridge, what is the easiest and least time intensive. I'm not interested in any of that as it has been discussed many times. I have read (and believe) that cleaning the interior by US does impact the velocity of the bullet. My question is does it improve consistency. You can always adjust your scope for dirty cartridges if having dirty cartridges only changes the velocity but not shot to shot velocity consistency. At the end of the day does cleaning your cartridge improve your chances of having a tighter shot group and lead to consistent velocity from reload to reload. I don't shoot large volumes so if it does make a difference I am willing to do the work.