little-d
I have shot a ton of sabots from my 50 Renegades and they shoot great. The "book" will tell you that you need to shoot shorter projectiles from a 1/48 twist but I never could get them to be as accurate as the longer 300 grain bullets. Then to even emphasize the point more I started shooting 460 grain Bullshops from my Renegades - awesome accuracy. I can shoot placed clay pigeons @ 125 yard with the Bullshops or the sabots and connect very easily. If I had better eyes to go along with the fiber optics I could easily extend that.
You mention .451 as a size - Speer does make a .451/300 grain Unicore it is not quite as good as a .452 Gold Dot but really shoots well for me. I amshooting 90 grains of T7-3f and a MMP HPH-24 sabot or a regular Harvester will work also.
I orginally, along time ago, tried .430/300 grain bullets (trying to get a better BC)in a Green sabot but could not really get them to be consistent through all of the shots... I would get a flyer every so often, but the Green sabots I was using back then were the old plastic type - the new Polymere sabots might perform better.
Shoot it you'll like it...