Just wondering, what is the weight difference between, say, a McWoody and a walnut stock of the same shape and size?
As said it is pretty hard to nail down. Most of the wood stocks I've weighed off common bolt rifles ran between 32-36 oz. One standard fill McMillan I have (Win FWT) is 30 oz. They advertise 32 oz on averge. My Edge stocks run 22-23 oz. There are other after market stocks weighing as little as 16 oz.
Just for reference the plastic tupperware stocks I've weighed tend to be the same as walnut and are often slighly heavier. Most of the cheaper synthetics such as B&C and Hogue are much heavier than wood,some weighing 40-48 oz.
