[B. Dudley]

There is also been recent discussion supporting that the weight stamps could indicate the weight of the barrels plus forend iron, since many who weigh their barrels with forend on come to within a couple ounces of the stamped weight.

I personally also beleive this is likely to be the case. It would give the workers putting a gut together an idea of what the front half of the gun woukd weight when putting it together with a back half to get a target weight and balance point for a given gun.