Ardent
AH enthusiast
Commercial loadings of each are identical, but the Rigby has a significantly larger case (136grs of H2O to the Lott's 110grs). So you're either using less pressure to do the same work, or pushing the bullet much faster at the same pressure if handloaded. Recoil from both is identical at the same velocity, despite a small on paper increase for the Rigby due to the extra powder. The Rigby is of course capable of being a .460 Weatherby if the handloader desires, something the Lott cannot come close to as it runs at essentially maximum already for the case. Loaded to .460 velocity, the .450 Rigby generates substantial recoil in my 9 3/4lb rifle, and a lot of bark. The Lott in some rifles will hold one more cartridge in the magazine, due to its slimmer case, and will shoot .458 Win in a pinch.
Just have to choose the trade offs you prefer, both have advantages and disadvantages, I view the .450 Rigby as superior to the .458 Lott but also recognize the Lott's strengths (magazine capacity, and dual ammunition option in a pinch). The .450 academically is the superior round as it does the same velocity at lower pressure, or more velocity at equal pressure, with a slick non-belted case.
Just have to choose the trade offs you prefer, both have advantages and disadvantages, I view the .450 Rigby as superior to the .458 Lott but also recognize the Lott's strengths (magazine capacity, and dual ammunition option in a pinch). The .450 academically is the superior round as it does the same velocity at lower pressure, or more velocity at equal pressure, with a slick non-belted case.