Has anyone ran a g2x on a rifle for awhile with it close to the muzzle break? I picked up this thorntail mount up locally for a good price and was hoping to install my g2 led on it. Lo and behold its a 1" ring so I'm forced to try the g2x, or drop $20 on a new ring, which I don't want to do. Will the muzzle blast beat it to death? Would it even hold up if it was further back?

If this setup works well I might move the x300 from my primary rifle to my glock 17 and get another thorntail mount instead.

It will do just fine.  I wouldn't lose any sleep at all over it.

Lens will get carboned up.

Let a few drops of rubbing alcohol sit on lens a few minutes and then wipe it off with a rag.