so, with the sig's alloy frame is it a matter of routinely keeping the frame "greased" to prevent premature wear?
It certainly helps when you're dealing with metals of two different strengths to have a lubrication to mitigate wear on the frame. Personally I use a grease on rails regardless out of habit these days. You don't have to be fanatical about it, just replace when cleaning. Lots of options out there too. I like Shooter's Choice.