Correct. I purchased a CHG00100AV at Lowes. This unit will drive staples from 3/8" to 1 1/4". Therefore I'm lacking the capability of driving 1/4" and 5/16". Lowes carries two of the sizes but only on quantities priced and fit for a large army.
I have found the staples at a handfull of retailers (meaning each retailer has one size each). Amazon, Home Depot, Lowes, EBay, Craigslist, Ace, Google searches....
So now I need three different staplers to cover my needs.
Granted: I've had to educate myself with respect to crown size, leg length, guages of staples and of course crown type. Honestly I'm a bit overwhelmed by something that should no be that difficult.