I've deliberately loaded down a few cartridges. The first one I ever attempted was my 270 rifle. My somewhat recoil-shy cousin was getting into deer hunting, so I developed a lower recoiling load using a minimum charge of IMR 4064 behind a 130 grain Interlock. Can't remember the exact velocity, but it was in the lower 2,600s. My next attempt at a downloaded cartridge was a factory 460 S&W Encore barrel. With its low weight due to a thin taper barrel and lack of a muzzlebrake, I was honestly scared to shoot a full power load through it, so I developed a 45 Colt +p+ equivalent load using 250 grain XTPs and Unique powder at ~1,550 fps. When developing handloads for a 41 Magnum Ruger Blackhawk, I felt the recoil produced with a full power H110 load pushing 250 grain cast bullets to 1,230 fps was a bit much to be qualified as comfortable, so I used a load of Titegroup to get 1,000 fps instead.
Been meaning to try Trail Boss and 110 grain V-Max's in my 300 Weatherby to see if it will replicate supersonic 300 Blackout ballistics, but haven't got around to it yet.