"Good", free ballistics calculator?

Is there a good one online? I have my Spot-On app. I just want to compare to another calculator.

If anyone wants to run the numbers: 175SMK, .505BC, 2619fps.

Try this on for size....

Link

I mostly used the "Trajectory (Simplified)" calculator.

Seems pretty in depth to me. I don't know very much about this stuff, but after reading some and monkeying around, I was able to produce what I thought was some pretty accurate data for 22LR. I imagine someone who is into reloading and knows more than myself could find this very useful.