Re: weatherby series 11 vanguard
The Vanguard synthetic stocks are quite solid for a plastic stock. I have seven of them including a 338 Winchester Magnum. The stocks hold up very well and the rifles shoot very well. I just got a new S2 in 240 Weatherby. The stock on that one seems the same as far as strength. They certainly aren't as solid as an HS Precision or a laminated stock but they are very good in my opinion.
Good luck with your purchase.