If you're rists feel odd, then it's time to go for lighter weight else you will end up injuring yourself.

And at the age of 16, lifting heavy weights is not a good idea, you're body is not yet fully grown and it could seriusly stunt you're growth and cause back problems, I know at age fifteen I took up boxing(no longer though), I had to see a doc for a year about my back.
So be careful dude.