Originally Posted by WisconSniper
Put it in a savage SA and swap the bolt head out for a magnum one then just open it a wee bit if needed. Savage bolt heads are like $20. Plus a savage action will be cheaper than a Remington, especially for experimenting.
I did something kind of similar to what you want on a Savage long action that I had shot the barrel out on. Mine shoots .510 cal (so far 750 Amax, pulled M33, API, and 725 grain Lehigh Defense) instead of .500 bullets like the S&W. With a 2.370" case the long action is too short to load these longer projectiles to any length what so ever and eject without removing the bolt or load into the magazine. The 500 S&W has a conventional loaded length of around 2 1/4" and the short action savage can take rounds approx 3" so that may be feasible. There are some rather long .500 cal bullets out there so you need to determine what bullets you plan on shooting.
I had thought of building a 50 Alaskan Ruger #1 but after looking at the cost of buying one just to build on I looked elsewhere. I also looked into the Alaskan on a TC single shot and called what seemed to be the guru, JD Jones at SSK. After speaking with him on the phone a couple times I realized that his attitude...demeanor...(whatever) sucked and I was not going to give him a single cent of my money.
I had thought of a 500 S&W NEF. I have one in .223 and it shoots pretty decent. However, I spoke to a buddy that has one in 45-70 and he says that the hammer has broken more than once with factory Remington core-locts. Says it's not the best platform for heavy recoiling cartridges, and I wanted to shoot heavy projectiles with a suppressor.
Added: I didn't have to do anything to the Savage bolt, it already have a magnum bolt head. The case I use is a shortened .300 ultra mag and it's rim is only slightly smaller than the .500 S&W.