As Texas10 said, if you are loading on a node the minor variation in case capacity of quality brass should not take you out of the node.
Here is what one member who is apparently very knowledgeable on the subject had to say regarding sorting by case weight in another thread:

KevinThomas
I’m not quite sure where all the conjecture relating to alloy and weight variation comes in, but as a rule, virtually everyone in the industry uses 70/30 cartridge brass for case production. Any other metals involved are little more than impurities, essentially trace elements within that 70/30 alloy. That’s not to say that the brass used by various manufacturers is the same, it most assuredly isn’t. Purity of the alloy, whether its virgin material or recycled blends, the production process that gives the material grain size and structure, all this comes into play as to how well the material will form, and just how good the end product will be. But I’d be shocked to see weight variations of any note being caused by differences in the alloy itself.
While many focus on case weight, it really isn’t a good indicator of capacity at all. Variation in case capacity is controlled primarily by the punches used in drawing the cases. As they come off the presses, the partially formed cases should have virtually identical capacities, assuming there’s nothing changed during that portion of the run. Weight variations in finished cases are the result of other operations that are performed on the case exterior, such as the heading operations that creates the primer pocket, flash hole and cuts the extractor groove. None of these have any bearing on the internal capacity, but very slight variations in how these operations are performed can greatly effect the weight of the finished case.
So why is case weight variation such a hot topic? Because on the face of it, it makes sense that it should be indicative of some difference, and internal capacity would seem to be a likely candidate for being that variable. Ani’s their very simple reason is that case weight variation is very easy to check, while actual water capacity is a real pain in the ass. As a result, many folks will take the fast and easy approach, downplaying the fact that it’s not giving you good data.
My advice here is, take note of the case weight when comparing different brands or runs of cases, and take really significant differences as a good reason to check the actual capacity via water. Aside from that,if you’re dealing with quality brass to begin with, that variation probably isn’t going to be a real concern in the finished product.
Here is what one member who is apparently very knowledgeable on the subject had to say regarding sorting by case weight in another thread:

KevinThomas
I’m not quite sure where all the conjecture relating to alloy and weight variation comes in, but as a rule, virtually everyone in the industry uses 70/30 cartridge brass for case production. Any other metals involved are little more than impurities, essentially trace elements within that 70/30 alloy. That’s not to say that the brass used by various manufacturers is the same, it most assuredly isn’t. Purity of the alloy, whether its virgin material or recycled blends, the production process that gives the material grain size and structure, all this comes into play as to how well the material will form, and just how good the end product will be. But I’d be shocked to see weight variations of any note being caused by differences in the alloy itself.
While many focus on case weight, it really isn’t a good indicator of capacity at all. Variation in case capacity is controlled primarily by the punches used in drawing the cases. As they come off the presses, the partially formed cases should have virtually identical capacities, assuming there’s nothing changed during that portion of the run. Weight variations in finished cases are the result of other operations that are performed on the case exterior, such as the heading operations that creates the primer pocket, flash hole and cuts the extractor groove. None of these have any bearing on the internal capacity, but very slight variations in how these operations are performed can greatly effect the weight of the finished case.
So why is case weight variation such a hot topic? Because on the face of it, it makes sense that it should be indicative of some difference, and internal capacity would seem to be a likely candidate for being that variable. Ani’s their very simple reason is that case weight variation is very easy to check, while actual water capacity is a real pain in the ass. As a result, many folks will take the fast and easy approach, downplaying the fact that it’s not giving you good data.
My advice here is, take note of the case weight when comparing different brands or runs of cases, and take really significant differences as a good reason to check the actual capacity via water. Aside from that,if you’re dealing with quality brass to begin with, that variation probably isn’t going to be a real concern in the finished product.