Telperion,
"That's the thing Dave, I'm new and not sure what counts as acceptable tolerances in fit. So, here is a typical picture of a brass being offered up to the sizing die. Looks off center to me (and the turret is firmly in a detent, auto-index off), but it pops the primer out fine, and the case chambers. If that's within limits, it would make me feel better to hear it from someone more experienced."
I think I can help you with your problem. Yes, you're over analyzing, which is ok, shows you're paying attention. Here's what is happening:
1. The tilt you're seeing there is normal. Your case holder on your ram has fairly loose tolerances to allow you to quickly insert and remove cases during the reloading process. In fact, it's loose enough to allow the case to tilt a bit.
If it were tight enough to absolutely prevent this tilt, you wouldn't be able to insert and remove cases very easily, if at all. But, you ask, will this affect accuracy? The answer is no, it will not. In fact, it will enhance the smooth functioning and alignment of your brass into the die.
But why doesn't it affect accuracy and how does it help alignment of the brass in the die?
It allows the case to move around and as the case is inserted into the die, align itself with the die. As the case raises into the die, the case/casehead will be square to the sizing die, while the case head may be slightly tilted to the case holder on the ram. It is the sizing die you want it to be square to, as it is the die, not the ram, that does the sizing.
Remember, your brass is a cylinder of soft sheet metal (brass) that's been expanded inside another cylinder (your chamber) to make a seal, then removed and has shrunk a bit. The object is to get it into another, smaller cylinder (your sizing die) to "resize" it back closer to it's original diameters to insure good feeding. To do this, you need the brass to center up with the sizing die. The looseness of the case holder allows this to happen. If the brass were held ridgidly in place, the brass would go into the sizing die at an angle and you'd get brass that was cocked.
So you're good to go. Don't worry about it and reload some rounds. The die will not necessarily make sizing marks on your brass evenly. But, if it's greatly concerning you, get a case gauge in your caliber (The Midway brand will do nicely.) and check your cartridges to insure they're right.
Regards,
Dave