Marty,
It all depends upon the size that your mold throws with
your alloy. Alloy content can make a considerable difference in the "as-cast" diameter of your bullets. If over, you'll certainly need to size them.
Now, about the sizing equipment. What pourboy suggested is exactly what I am going to suggest to you as well. Lee Precision has an excellent sizing setup that screws into your reloading press and sizes your bullets. The neat part is, that it takes up no more space to store than a set of sizing dies, and it works superbly! Also, if they don't have the exact size you need, they can make them to your specs and have a reasonable turn-around time, or do as I have done in the past, and simply lap them out to your desired diameter. Nice thing about these loading press mounted bullet sizing dies is that they size the bullet nose-first, so they self-center in the die, virtually eliminating the possibility of an eccentricly sized bullet, and the gas checks are seated squarely before getting crimped, all in the same step! Too, you don't have to buy separate nose punches for every mold you buy!
Check them out here:
While it is true that you can buy used lubrisizers that both lube the bullet and size it in one operation (and also take up lots of loading bench space) from the online auction sites at about half of retail prices, don't be tempted to buy the Lyman 450 Lubrisizer just because it is cheaper... they are cheap... they haven't done a redesign of the basic lubrisizer in many decades, and the design has some serious weak points... evidenced by the number of Lyman 450's that you will see used with brazed or rewelded handles, linkages home-made that are beefier than the factory ones. If buying a run-of-the-mill lubrisizer, get the RCBS machine, or if you want to add another 50-75 dollars to the acquisition cost, buy the best and get a Star, available from Magma Engineering.
Check it out too!
For now however, the Lee Precision unit will do many, many thousands of bullets, and the quality won't be one whit better than those done on a Star Machine! You will need to either hand lube or pan lube, as mentioned earlier.
Another method that I used extensively in my earlier hobby-casting days (read tight budget casting/shooting in high-school & college) for lubing, was to have a shallow pan of lube melted, (usually over the top of my lead-pot), then dip my room temperature bullets into the lube, quickly, holding on to the nose, and dipping the bullet to a depth equal to the crimp groove on the bullet. In this fashion, the lube stayed on the cold bullet, much like making a candle, then when I put the bullet down, I stood it nose-up in a shallow metal box, then when I was ready to size them with the Lee Sizing unit, I simply scraped the base of the bullet on the semi-sharp edge of the metal box to remove what little lube remained on the bullet base, applied a gas-check and ran the bullet through the Lee sizing die. Worked like a charm, filled the grooves and they shot wonderfully! I never did like the cake-cutter method, although scores of casters swear by the technique, I was always too impatient for that, I wanted to get volumes of bullets done so I could go shoot my sixguns!
Hope these few ideas help... casting should be enjoyable. It needn't be expensive nor complicated unless you choose to make it that way. Excellent bullets can be cast and sized with only a fifty dollar investment, if one is frugal, thrifty and watchful for deals!
Hope we can be of help to you here on the forum!
God Bless,
Marshall