Haven't done it on a 91 but I had Ghillie build me a 51k some years ago and had a 22 kit modified for use with it. Had the barrel threaded 1/2x28 as it was primarily built to be a 22 host. Gun runs perfect with CCI ammo in semi or full with a Tactical Innovations Quest suppressor. Kit does not like the cheap ammo or subsonic ammo but with CCIs it is a sewing machine.
Do a search on my user name and "22 conversion kit" in the Range Report section and you can get my full writeup from years ago. The only thing that didnt work well was burst mode, as the recoil isn't strong enough to turn the burst counting wheel.
I fooled around with a .22 kit and a Bazooka Bros. mag conversion for the AM 180 magazines. It functioned perfectly once I got the magwell adapter fitted and gave the rifle a magazine that was worthy of full-auto. Never did try a can on it though.
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