I have experince with the Savage 410ga liners in a single trigger 12ga double. I found the shot pattern was too big and open, and the 410ga recoil was not strong enough to work the selector to switch over to the next barrel for the second shot, so I had to kind'a give the butt plate a slap to make the selector work.
So, try a full length 410 linner that goes all the way to the muzzle for the best patterns, and unless you have a gun with 2 triggers, you might need the selector lightened up so the recoil will switch it over to the next barrel.