What you guys fail to understand is that a rocket booster is NOT armored. The entire structure has been pared down to minimize weight. The whole development effort is to find out where things can be "lightened" safely, and what things cannot. NONE of it is designed to withstand a bullet impact. This is a fragile mechanism, upon which one does not need to impact with massive kinetic energy to cause catastrophic damage, you just need to weaken something to the point where the high stresses of takeoff will start a chain reaction of breakage. So no, you do NOT need a 0.50BMG or Lapua to "take it down".
A .308 Winchester has 2700 ft-lbs of energy at the muzzle, and 270 ft-lbs of energy at 1700 yds.
Worse, if your rifle is zeroed at 250 yards, the bullet will drop a staggering 2,000 inches at 1700 yards.
If you want to make a 1700 yard shot, you will use a .50 BMG or a .338 Lapua.
What you don’t understand is the formulation process. If I were going to try and shoot down a billion dollar bird I wouldn’t leave impact on the drawing room floor... For no good goddamn reason.