I am looking at blanks for a 500 A2; what are the minimum dimensions of a suitable blank for a heavy rifle? is 2.5" thickness at the butt end, tapering to 2.25" towards the fore-end too little?
Thanks!

I am not a stockmaker, but looking carefully at a stock seems to provide the answer you are looking for. I would think that what you intend to put on the butt end of the stock plus the the thickness of a cheekpiece would dictate how thick the butt end should be. The width of your cheekpiece would be dictated by how wide your face is, as well as your style of shooting (i.e where on the stock you place your cheek, how you hold the gun, etc.) But obviously, the width of your receiver also comes into play. YOu may want a real narrow recoil pad for some reason (probably not on a big boomer) but you still need to have plenty of room to fit that receiver plus anything abutting up to the side of that receiver, such as the bolt release on a mauser action.

Speak with your stockmaker about the width of cheekpiece that is right for you and your recoil pad preference and you can then determine how wide you need the butt end to be.