Knighthawk,
Unfortunately, rechambering to .250 Ackley Improved does NOT reduce "bolt thrust," despite P.O. Ackley's experiments. Both the .250 Savage and .30-30 were serious flawed, which one of the the chapters in my book GUN GACK II explains in depth--along with other misconceptions about case shape and bolt thrust.
Plus, I would NOT rechamber old classics like yours, not just because it would reduce the resale value (which it will) but because there's no real reason to, if what you want to do is kill deer. I say this as a long-time .250 and 99 nut, who at one time owned SIX Savage 99 .250-3000's, and have also owned a bunch of other .250's, including a Savage Model 20, along with a bunch of others, including some other brands of factory rifles and more than one custom rifle.
While there may be some small ballistic advantage in the .250 AI, it's more theoretical than real. In the past 35+ years, my wife and I have killed a bunch of big game from pronghorn to elk with the .250, along with the .257 Roberts, .257 Roberts Ackley Improved, .25-06 and .257 Weatherby Magnum. Our experience is that they all kill well--if the right bullet lands in the right place. One of the virtues of the .250 is the muzzle velocity makes a lot of bullets (including some under 100 grains) the "right" bullet.
