Okay, I got a reply from Ben (greywolf, I think) on the VM owners group saying that a VM gets 60 shots per ounce straight and 100 per oz regged/EC'd/tuned. It's probably a pretty liberal estimate, but it's probably pretty close if you subtract 10shots/oz.
"There's nary a beast that can outrun a greased-up scotsman!" - Willie
"What makes a VM so charming is that you can chop down small trees with it" - Jaan