tips and tricks?

In need of some helpful tips. My son is 5 months old and we've been using the swaddle me's and the halo wraps since he was 1 and a half month old. He loves them and sleeps longer in them. But now since he's getting so big at the weight of 20 lbs and height of 27 inches tall it is getting harder to find the wraps. We have sleep sacs but it doesn't hold his arms down. He likes that but then gets his arms out later in the night. Where I need tips from is how to transition him easily and calmly into sleeping arms free and in the the sleeping sacs