My experience was on my M99 using an Arizona-made production can and also a one-off custom can, both for the M82. As you can imagine, the recoil was more than one could tolerate on the single shot. We also shot muffs-off and weren't bothered, though we still had plugs in. I observed the recoil to be 7-8", regardless of who shot (large or smaller person) or how (free recoil or shoulder into gun), and that the recoil built up rapidly (about 6 shots each max). We didn't shoot all the ammo that was available; not by a long shot.
Also used Elite Iron's 50 can on another 50 and also on an Encore in 50 Alaskan. I will have a suppressed 50 Alaskan to shoot subsonic API! The EI can on the BMG was quieter than the others mentioned above, and had better recoil reduction. On the Encore with subs, it was stupid quiet, with about the same recoil as dryfire (that is an exaggeration - it was more like a 308 with 220 grain bullets).
Your mileage may vary. Contact any 50 manufacturer and ask them their experiences and recommendations. Try EDM first; they make the Windrunner.
