^^^ Will. My ciders generally finish in the 0.996-0.998 range. Just a rough calculation, if it finishes dry (and it probably will), you're looking at about 6 volumes carbonation. The only thing that will hold that kind of pressure is heavy champagne bottles. Beer bottles will shatter well before you get to those levels of pressure.
How long have they been bottled? If it has been less than a week, I'd recommend you open one every day or so to monitor pressure. Once they hit sufficient carbonation, and I'd err on the low side, I would seriously look into bottle pasteurization to kill the yeast.