Though you're addressing Val for information maybe he won't mind if I offer my opinions. I'd personally stay away from waterborne clears for a gun stock job. I could go into technical depth on this but I'll just touch on a couple of issues . 

First of all the good WB ( waterborne ) clears are catalytic or two part. For a small job like this two part systems are cumbersome and generally wasteful since packaging and ratios are set up for larger jobs. Secondly most gunstock jobs are typically wiped on and hand rubbed and most waterborne clears dry fast and a bit temperamental. The clears are ' water-white ' so they don't leave a warm amber like color to your wood. To achieve any tint or color you'll have to stain so you're now into a multiple step finish schedule and with tinting and color most discerning users almost always find themselves testing stain colors until they are happy. WB clears are not nearly as durable as oil based so they scratch and abrade easier and touch up is tricky to say the least as the stuff doesn't blend easy, if at all. If you intend to brush or spray then other problems are possible. 

Rick
 

Thank you both.