Re: .300 WSM ?
Well first off, I have 4 300 WSM's all sporters. I was a big fan of the short fat cartridges when they came out, and still like them a good deal. Feeding CAN be a huge issue, that is certain. Newer designs (last 4 or 5 years IMO) mfgs. have been making dedicated rigs for these cartridges, and feeding is not the issue it once was, but regardless of that, a short fat cartridge is not a gunsmiths ideal for smooth feeding! The center feed DBM magazines eliminate this issue to a large degree. I have several of my SM's in Sako rifles, and they are staggered box DBM's and they feed without issue, always have.
As to the WSM (300 or any other) being expensive to load for, I don't understand that comment--the brass lasts longer than 300 WM IME, and is readily available. It uses LESS powder...it is more efficient, but will not run with the 300 WM with heavier pills, I think a 180 is max for me the SM, and typically run 165's or 168's in mine. If you want to run the heavier pills I'd go a 300 WM or 300 Dakota if you want some out of the norm. If looking at factory ammo, it is pretty close in price, I just looked on Midway, and if anything some of the 300WM was a bit higher than the WSM, but all in all pretty darn close in $.
I have not experienced the difference in recoil that at least one poster indicated, in fact quite opposite, my 300WM punches me hard and quick (same weight bullets in both rigs) and my WSM's in two different stock designs, (Sako Hunter and Rem Sporter) push more so....probably more to do with the specific stock design from rifle to rifle than actual recoil, all the 'tech studies' I have seen say there is a slightly less recoil in the 300 WSM, but it is splitting feathers so to speak.
I'd build one in a second, a lot of match shooters like them and have results to back there liking them up.......not that there aren't tons of the same with the good ole 300 WM too