Re: 243 for White deer, What bullet?
Any decent bullet from a reputable manufacturer will work fine, though I would steer clear of the varmint bullets. The real question is what will shoot well in your particular gun, (most every bullet out there will work fine if you shoot it well and place it properly on the animal) your accuracy and placement far outweigh bullet selection. The only way to find that out is to try several different bullets/loads.
My typical procedure for finding a bullet starts out with choosing a couple or three bullets, said bullets will always share a few characteristics; heavy for caliber (barrel twist permitting) As high as a BC as possible, and last but not least, an affordable bullet available most everywhere.
My reasoning is derived from the volume of shooting I do, If I shoot Bergers VS. Hornady's I will just plain have to shoot less because of the cost. The heavier bullets usually have the better BC, as well as good performance on the big game that I typically pursue. I find it wasteful and tedious to have multiple loads for competition, hunting, varminting, Zombies, ect. We spend countless time and money trying to uniform brass, bullets, stocks, barrels and such for the sole purpose of removing variables, variables are what kill our consistency and thereby our shot to shot accuracy. I dont know why people go to all that work, and then throw a huge variable into their equation with a new/different bullet.
My bullet selection almost always begins with Hornady and Sierra, reason being they are very affordable, and have an excellent performance history with myself and others. And they do so without putting my home up as collateral.
If I were to start playing the .243 game, I'd start with either a 105 Amax or a 107 SMK, though your barrel likely is not twisted right for those two. That being the case one of the lighter bullets like and interlock, SST, or a Game King would probably do you well. Something in the 85- 95 grain.
Good luck with your choices, enjoy the chase after the perfect load.