Atonement

As a reformed guy, I believe in a limited atonement. What exactly does that mean, you ask?

Well, as best as I can understand it, Christ's death on the Cross was for particular individuals (all those that would ever be saved) and for their particular sins. Another view would take the tack that Christ's death on the Cross made it possible for everyone to come to the Father through Christ. Now we most of us would agree that not everyone is going to be saved (though there are some who do believe that), whether we think it to be by "free" will or by God's ordaining it.

Rather than try a long, drawn out discussion, let me posit one question to those who simply state that Christ's death made it "possible" rather than guaranteeing salvation:

If Christ died for everyone, then it is very probable that He died for the sins of those that will end up in Hell. Would that mean that His blood was in some instances shed in vain, or that its power is somehow lacking?