Put me in the Lead Sled mistake club.
Me too. i see a guys sight in their guns using a lead sled and never fire the gun from their shoulder: This is a mistake. In several cases i'm aware of its cost hunters deer and elk and caused long tracking jobs.
Among my guns there is only one rifle whose recoil i consider severe: That gun is a 6.5 pound lightened Thai Mauser in .375 Alaskan (.348 Winchester case blown out and necked up). In terms of recoil; think a heavy load in a light .375 H&H magnum.