THANKS, 'Tikka and 'Stove!

I'd hate to have to decide which'd be more welcome -- confirmation or correction. Whichever, I'm glad to have the correct equation again -- have made it into a Mathcad work sheet so that all I have to do is enter the values of a and b for any tested bullet and get its x automatically -- then enter the value of x so derived and get the density (gr/cu in.) of the tested bullet from another equation. Nice and handy.

THANKS again!

"Good enough" isn't.

Always take your responsibilities seriously but never yourself.