Liberty just started making a new .458 can. I've never used their rifle cans, but I use their .22 cans exclusively (the new Regulator may be the best .22 can ever built to date, seriously). I have the all titanium Essence too, nice, but that Regulator kicks it's ass and is only a an ounce or so more and way simpler to clean. I have their Pinnacle 2 10-22 integral barrel, considering having it modified to a take down, but haven't done anything with it. A 4.5"bbl. and 11.5" suppressor built into a solid Green Mountain barrel should be awesome. I also have their Mystic X, my only modular can and it's quiet but I only use for 9mm; should have just bought a good dedicated 9mm can. I do have the Omega 9k and it's just great.
So I called them about having it modified to a .50 Beowulf but they couldn't do it. The numbers don't show suppression of these rounds to be too great, but never heard them in person. The Beowulf has tremendous power, but it has a serious limited range on the order of 100-200m maximum, depending on load. In the end, I decided not to spend the money to suppress the Beowulf. They make 'em, but they are costly. Forget who actually makes them though. It adds length and it'll still be loud, so I'll probably just put a brake on it some day (I got this thing prior to 2004).
Not sure if the .458 has the same power or the same problems with short range, but I can't see it being worth suppressing. I'd buy cans for other rifles instead.