With 1st DS - I found swaddlers were great for really NB babies, but I found you had to size up in a short time and they are really expensive. Also found regular receiving blankets were to small. So I went to a fabric store and bought some flannel on sale and cut the blanket square - as long and the fabric was wide, 45" I think. They worked the best. I could get a tight swaddle and he couldn't kick out.
So for DD we just stuck right with the xtra large receiving blankets from the get go. They were so much handier and for the same price as one swaddler, you could litterally have 30 - which was good since my babies were pukey and I often needed to use a fresh blanket for every nap.
I swaddled DD in these from birth till 7 months then went to a sleep sac.