The .450 Watts and Lott both used the full length .375 H&H case. If the .300 Win Mag model Savage you have can handle this length, then the answer is yes.

About the only difference between the Lott and Watt's cartridges as I understand it, is the Lott's sloping "Mean Little Shoulder" - ie: no mean little shoulder as in a normal rifle chamber.

Due to the gradual angle up into the throat of his chamber, shooting short rounds like the .458 Win Mag will not scrape bullet jacket material off the the bullet as it enters the chamber's leade then throat.

Due to normal chamber shape of the Watt's this scraping or cutting of jacket material is likely to happen - injure the bullet jacket's integrity and also cause innacuracy. The Lott should be more accurate with any shorter cases than 2.850".

Jack Lott said this was the sole reason for his chamber's shape.