Blastdown rhymes with:
countdown, letdown, meltdown, piltdown, putdown, shootdown, shutdown, writedown, ashdown, breakdown, clampdown, closedown, comedown, countdown, crackdown, drawdown, godown, hillsdown, hoedown, knockdown, lansdowne, letdown, lockdown, lowdown, markdown, meltdown, piltdown, putdown, rundown, shakedown, shootdown, showdown, shutdown, slowdown, southdown, sundown, touchdown, turndown, underdown, writedown
Blastdown sounds like:
blackston, blackstone, blagden, blaustein, bluestein, bluestine, bluestone, blystone, boyleston, boylston