what swaddle do you use?

My 15 week old, 15lber, who is not rolling over yet, still loves to be swaddled tight for bedtime. The problem is he's getting too big for the muslin swaddles. We tried upgrading to a sleep sack with his arms free, Merlin sleep suit, and swaddling him in the muslin swaddles arms free, but it doesn't seem to be the same. He won't sleep longer than 20 minutes in those. Anyone still swaddling? If so, what are you using? *also, we tried no swaddle.... definitely not ready yet. We've been trying all these things for the past 2-3 weeks now.