Psssssst Jimbo, I'm going to let you in on a little secret buddy, so listen closely.
Proponents of the SBT don't have to explain any missing bullets.
They don't have to explain what happened to 'both shots', because they believe one shot caused the non-fatal wounds to JFK and JBC, and that 399 is the bullet that did the wounding.
The explanation for what happened to the bullet that entered JFK's back/neck region is simple, it exited his throat and went on to hit JBC.
By the way Jimbo, I've been taking it easy on you kooks. If as you say the back shot never exited, that means there are two vanishing bullets for you to account for.
Even if you could account for the bullet that entered JFK's back and never exited, that still wouldn't get you off the hook for explaining what happened to the bullet that entered JFK's throat, now would it, Einstein ?
There's nothing baffling about the SBT.
What is baffling, is that if the SBT is wrong, what happened to the bullet that supposedly entered JFK's throat. ?
I'd say it's baffling how the drooling kooks can go on insisting there was a frontal entry neck wound, when they can't explain what happened to the bullet. Actually, that's not really baffling it all. That's what drooling kooks do. Amusing, yes. Baffling, no.
So Jimbo, now that that's been explained to you, feel free to explain what happened to the bullet that entered JFK's throat.
Challenge still stands, droolers.