My opinion is this is the direction manufacturers would like to head. No doubt the rubber insert cost less for them to make than to have someone checker the stock. They will extol the virtues of it, but the reality is it's just a cost cutting mechanism.
While I understand there are some benefits to synthetic stocks, I think the big push by the makers has more to do with profit than practicality.
Here's a nice piece of wood on a typical Swedish hunting rifle by VO Vapen. I kid, these things go for US $300K-800K. Usually bought by kings and sheiks, not something you throw in your Koenigsegg as a truck gun.
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