Another lesson you are about to get, when you buy your next batch of components, is that all batches are not exactly alike. It makes good sense, once you've established the load and components, your going to settle on to buy large quantities.
Larger tubs of powder, like the 8lb tubs, 1000 primers at a time, 1000 bullets at a time. Don't buy a buch of 1lb tubs of powder, unless they are from the same lot. The same goes for primers and bullets. Not all lots are created equal is a good thing to remember. If you start out with different lots, frequently, you will be frequently testing your loads, instead of having confidence in what you have at hand. If you can't get the larger tubs, pour all of the powder into one large container and blend them together. Please, don't mix up different powders, the results will be less than exhilerating.
Buying in bulk, will save money as well. Dealers get a better deal for volume and pass on the savings. If they don't, try another dealer. I haven't come across one that hasn't though.
stubblejumper, factory loads, can and do change, from one lot to the next. It isn't uncommon for factories to change powders, or powder lots from one batch of ammunition to the next. The same goes for primers and bullets. They usually go with the best quality powder in a similar burning range, bullets in the same shape and weight range and similar primers, for the least cost or even availability, in the quantities required at scheduled loading time. Even the brass case, can come from different manufacturers and as with the other components, only has to be manufactured to whatever specifications are agreed upon. Way to many variables to go on blind faith. Then again, there is always some lucky SOB, that has a rifle, that will digest anything put through it, as if it were a special match load, tailored to the rifle. They are few and far between. I have a couple, and no way in hell will they ever be sold.