For years I just ordered Brown's made of fiberglass for 300's 338's and 375's. Some had graphite reinforcement here and there and some did not. All shot well and like Scott said they tend to flex a bit so even hard recoiling rifles were comfy.
At the same time friends and I had 4-5 McMillans made for Sako's and bedded M70's in them chambered 300 mags and 338. These were stiffer.
Have had only 3 recent McMillans; two Edge and one mag fill in 375. So, I go by what Gene and Darcy have to say and both urge standard or mag fill for 300 mags and up.They seem to know this based on building custom rifles and watching what shoots/works and what does not consistently and over the long haul.
I handled a raw unbedded Legend standard fill the other day built for a 375 H&H;it was cross bolted. Since it came from DArcy I'd have built a 338 or 300 mag,or 375 H&H on that stock n a heartbeat. I may STILL buy it... nice stock!
